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Sample records for bearing nci-460 lung

  1. The sweet lung: Chewing gummi bear aspiration

    PubMed Central

    Tavladaki, Theonimfi; Fitrolaki, Michaela-Diana; Spanaki, Anna-Maria; Ilia, Staurula; Geromarkaki, Elissabet; Briassoulis, George

    2012-01-01

    Inhalation of foreign bodies, a leading cause of accidental death, is most common in preschool children. In this article we report our experience with a 5-year-old Greek girl who presented with a 24-hour history of sore throat, chest pain, and shortness of breath. Emergency bronchoscopy was performed and multiple small chewing gummi bear (HARIBO) particles impacted in the orifices of the right main bronchus and right lobar and segmentalinic bronchi were successfully removed and aspirated. Aspiration of gummi bears, which is for the first time reported, may cause a silent choking episode leading to life-threatening bronchi obstruction at multiple sites, even in children older than 4 years. PMID:22919167

  2. Curcumin reduces trabecular and cortical bone in naive and Lewis lung carcinoma-bearing mice

    USDA-ARS?s Scientific Manuscript database

    The present study investigated the effects of dietary supplementation with curcumin on bone microstructural changes in female C57BL/6 mice in the presence or absence of Lewis lung carcinoma. Morphometric analysis showed that in tumor-bearing mice curcumin at 2% and 4% dietary levels (w/w) significa...

  3. Radiation-induced lung fibrosis in a tumor-bearing mouse model is associated with enhanced Type-2 immunity.

    PubMed

    Chen, Jing; Wang, Yacheng; Mei, Zijie; Zhang, Shimin; Yang, Jie; Li, Xin; Yao, Ye; Xie, Conghua

    2016-03-01

    Lung fibrosis may be associated with Type-2 polarized inflammation. Herein, we aim to investigate whether radiation can initiate a Type-2 immune response and contribute to the progression of pulmonary fibrosis in tumor-bearing animals. We developed a tumor-bearing mouse model with Lewis lung cancer to receive either radiation therapy alone or radiation combined with Th1 immunomodulator unmethylated cytosine-phosphorothioate-guanine containing oligodeoxynucleotide (CpG-ODN). The Type-2 immune phenotype in tumors and the histological grade of lung fibrosis were evaluated in mice sacrificed three weeks after irradiation. Mouse lung tissues were analyzed for hydroxyproline and the expression of Type-1/Type-2 key transcription factors (T-bet/GATA-3). The concentration of Type-1/Type-2 cytokines in serum was measured by cytometric bead array. Lung fibrosis was observed to be more serious in tumor-bearing mice than in normal mice post-irradiation. The fibrosis score in irradiated tumor-bearing mice on Day 21 was 4.33 ± 0.82, which was higher than that of normal mice (2.00 ± 0.63; P < 0.05). Hydroxyproline and GATA-3 expression were increased in the lung tissues of tumor-bearing mice following irradiation. CpG-ODN attenuated fibrosis by markedly decreasing GATA-3 expression. Serum IL-13 and IL-5 were elevated, whereas INF-γ and IL-12 expression were decreased in irradiated tumor-bearing mice. These changes were reversed after CpG-ODN treatment. Thus, Type-2 immunity in tumors appeared to affect the outcome of radiation damage and might be of interest for future studies on developing approaches in which Type-1-related immunotherapy and radiotherapy are used in combination. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  4. Reliability and minimal detectable change of the weight-bearing lunge test: A systematic review.

    PubMed

    Powden, Cameron J; Hoch, Johanna M; Hoch, Matthew C

    2015-08-01

    Ankle dorsiflexion range of motion (DROM) is often a point of emphasis during the rehabilitation of lower extremity pathologies. With the growing popularity of weight-bearing DROM assessments, several versions of the weight-bearing lunge (WBLT) test have been developed and numerous reliability studies have been conducted. The purpose of this systematic review was to critically appraise and synthesize the studies which examined the reliability and responsiveness of the WBLT to assess DROM. A systematic search of PubMed and EBSCO Host databases from inception to September 2014 was conducted to identify studies whose primary aim was assessing the reliability of the WBLT. The Quality Appraisal of Reliability Studies assessment tool was utilized to determine the quality of included studies. Relative reliability was examined through intraclass correlation coefficients (ICC) and responsiveness was evaluated through minimal detectable change (MDC). A total of 12 studies met the eligibility criteria and were included. Nine included studies assessed inter-clinician reliability and 12 included studies assessed intra-clinician reliability. There was strong evidence that inter-clinician reliability (ICC = 0.80-0.99) as well as intra-clinician reliability (ICC = 0.65-0.99) of the WBLT is good. Additionally, average MDC scores of 4.6° or 1.6 cm for inter-clinician and 4.7° or 1.9 cm for intra-clinician were found, indicating the minimal change in DROM needed to be outside the error of the WBLT. This systematic review determined that the WBLT, regardless of method, can be used clinically to assess DROM as it provides consistent results between one or more clinicians and demonstrates reasonable responsiveness. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Lung-targeting drug delivery system of baicalin-loaded nanoliposomes: development, biodistribution in rabbits, and pharmacodynamics in nude mice bearing orthotopic human lung cancer

    PubMed Central

    Wei, Yumeng; Liang, Jing; Zheng, Xiaoli; Pi, Chao; Liu, Hao; Yang, Hongru; Zou, Yonggen; Ye, Yun; Zhao, Ling

    2017-01-01

    The present study aims to develop a kind of novel nanoliposomes for the lung-targeting delivery system of baicalin as a Chinese medicine monomer. Baicalin-loaded nanoliposomes were prepared by the effervescent dispersion and lyophilized techniques. Baicalin-loaded nanoliposomes had an average particle size of 131.7±11.7 nm with 0.19±0.02 polydispersity index, 82.8%±1.24% entrapment efficiency and 90.47%±0.93% of yield and sustaining drug release effect over 24 h and were stable for 12 months at least. In vitro no hemolytic activity was observed for the experimental drug concentration. After intravenous administration of baicalin-loaded nanoliposomes to rabbits, drug concentration in the lungs was the highest among the tested organs at all time points and was significantly higher than that of its solution. For the targeting parameters, the relative intake rate and the ratio of peak concentration of lung were 4.837 and 2.789, respectively. Compared with plasma, liver, spleen, and kidney, the ratios of targeting efficacy (Te)liposomes to (Te)injection of lung were increased by a factor of 14.131, 1.893, 3.357, and 3.470, respectively. Furthermore, the results showed that the baicalin-loaded nanoliposomes did not induce lung injury. Importantly, baicalin-loaded nanoliposomes showed better antitumor therapeutic efficacy in the nude mice bearing orthotopic human lung cancer with the median survival time of blank liposomes (11.40±0.16 days), baicalin solution (17.30±0.47 days), and baicalin-loaded nanoliposomes (25.90±0.53 days). Therefore, the liposome is a promising drug carrier with an excellent lung-targeting property and therapeutic effect for the treatment of lung disease, such as lung cancer. PMID:28096670

  6. Lung-targeting drug delivery system of baicalin-loaded nanoliposomes: development, biodistribution in rabbits, and pharmacodynamics in nude mice bearing orthotopic human lung cancer.

    PubMed

    Wei, Yumeng; Liang, Jing; Zheng, Xiaoli; Pi, Chao; Liu, Hao; Yang, Hongru; Zou, Yonggen; Ye, Yun; Zhao, Ling

    2017-01-01

    The present study aims to develop a kind of novel nanoliposomes for the lung-targeting delivery system of baicalin as a Chinese medicine monomer. Baicalin-loaded nanoliposomes were prepared by the effervescent dispersion and lyophilized techniques. Baicalin-loaded nanoliposomes had an average particle size of 131.7±11.7 nm with 0.19±0.02 polydispersity index, 82.8%±1.24% entrapment efficiency and 90.47%±0.93% of yield and sustaining drug release effect over 24 h and were stable for 12 months at least. In vitro no hemolytic activity was observed for the experimental drug concentration. After intravenous administration of baicalin-loaded nanoliposomes to rabbits, drug concentration in the lungs was the highest among the tested organs at all time points and was significantly higher than that of its solution. For the targeting parameters, the relative intake rate and the ratio of peak concentration of lung were 4.837 and 2.789, respectively. Compared with plasma, liver, spleen, and kidney, the ratios of targeting efficacy (Te)liposomes to (Te)injection of lung were increased by a factor of 14.131, 1.893, 3.357, and 3.470, respectively. Furthermore, the results showed that the baicalin-loaded nanoliposomes did not induce lung injury. Importantly, baicalin-loaded nanoliposomes showed better antitumor therapeutic efficacy in the nude mice bearing orthotopic human lung cancer with the median survival time of blank liposomes (11.40±0.16 days), baicalin solution (17.30±0.47 days), and baicalin-loaded nanoliposomes (25.90±0.53 days). Therefore, the liposome is a promising drug carrier with an excellent lung-targeting property and therapeutic effect for the treatment of lung disease, such as lung cancer.

  7. MicroRNA-2 suppresses Lewis lung cancer cells proliferation, invasion, and migration in tumor-bearing mice.

    PubMed

    Wang, Xu; Wang, Ping-fan; Yuan, Wu-ying

    2014-12-01

    We sought to find the biological effects of MicroRNA-2 in suppressing Lewis lung cancer cells proliferation, invasion, and migration in tumor-bearing mice. MicroRNA-2 was transfected into Lewis lung cancer cells of tumor-bearing mice by gene transient transfection technique and these Lewis-microRNA-2 cells were taken as MicroRNA transfection group. At the same time, Lewis cells were taken as control group and Lewis-EGFP cells as empty plasmid group. The growth curves of cells in the three groups were drawn by manual counting method, while the invasiveness of cells in the three groups was compared by transmembrane cell invasion assay. The three kinds of cells were seeded into BALB/Nude SPF level nude mice to detect the formation of tumors and the number of metastases by Xenograft experiments. The result showed that the MicroRNA transfection group has the lowest vitality of cells proliferation, fewest cells passed through matrigel matrix protein layer, and lowest cells invasive rate. Mice with Lewis-microRNA-2 cells apparently had a longer time of tumor formation. The average tumor mass and the number of metastases were significantly lower than the other two groups. MicroRNA-2 significantly inhibited Lewis lung cancer cell proliferation, invasion and migration in tumor-bearing mice, which may be associated with the regulation of target genes PLK1 and TGF-β.

  8. Validity of clinical outcome measures to evaluate ankle range of motion during the weight-bearing lunge test.

    PubMed

    Hall, Emily A; Docherty, Carrie L

    2017-07-01

    To determine the concurrent validity of standard clinical outcome measures compared to laboratory outcome measure while performing the weight-bearing lunge test (WBLT). Cross-sectional study. Fifty participants performed the WBLT to determine dorsiflexion ROM using four different measurement techniques: dorsiflexion angle with digital inclinometer at 15cm distal to the tibial tuberosity (°), dorsiflexion angle with inclinometer at tibial tuberosity (°), maximum lunge distance (cm), and dorsiflexion angle using a 2D motion capture system (°). Outcome measures were recorded concurrently during each trial. To establish concurrent validity, Pearson product-moment correlation coefficients (r) were conducted, comparing each dependent variable to the 2D motion capture analysis (identified as the reference standard). A higher correlation indicates strong concurrent validity. There was a high correlation between each measurement technique and the reference standard. Specifically the correlation between the inclinometer placement at 15cm below the tibial tuberosity (44.9°±5.5°) and the motion capture angle (27.0°±6.0°) was r=0.76 (p=0.001), between the inclinometer placement at the tibial tuberosity angle (39.0°±4.6°) and the motion capture angle was r=0.71 (p=0.001), and between the distance from the wall clinical measure (10.3±3.0cm) to the motion capture angle was r=0.74 (p=0.001). This study determined that the clinical measures used during the WBLT have a high correlation with the reference standard for assessing dorsiflexion range of motion. Therefore, obtaining maximum lunge distance and inclinometer angles are both valid assessments during the weight-bearing lunge test. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  9. Effect of interleukin-2 treatment combined with magnetic fluid hyperthermia on Lewis lung cancer-bearing mice.

    PubMed

    Hu, Runlei; Ma, Shenglin; Ke, Xianfu; Jiang, Hong; Wei, Dongshan; Wang, Wei

    2016-01-01

    The present study aimed to investigate the therapeutic effect of interleukin-2 (IL-2) treatment combined with magnetic fluid hyperthermia (MFH) on Lewis lung cancer-bearing mice. Magnetic fluids were prepared in vitro and directly injected into the tumors in the mice, which were subjected to an alternating magnetic field. The temperature in the tumor reached 43°C and was maintained by controlling the strength of magnetic field for 30 min. Twenty-four hours later, IL-2 was injected directly into the tumors. Mice were divided into four groups: Group I (control), II (MFH), III (IL-2) and IV (IL-2+MFH). The tumor grew gradually in groups II and IV (both P<0.05) compared to the control group. Histological analysis showed that the tumor cells underwent apoptosis and necrosis. Immunohistochemistry results demonstrated that heat-shock protein 70 and cluster of differentiation (CD) 8-positive and CD4-positive T cells were strongly expressed following hypothermia. Therefore, the present study provided evidence that IL-2 treatment combined with MFH improves the therapeutic effect on lung cancer-bearing mice.

  10. The TiltMeter app is a novel and accurate measurement tool for the weight bearing lunge test.

    PubMed

    Williams, Cylie M; Caserta, Antoni J; Haines, Terry P

    2013-09-01

    The weight bearing lunge test is increasing being used by health care clinicians who treat lower limb and foot pathology. This measure is commonly established accurately and reliably with the use of expensive equipment. This study aims to compare the digital inclinometer with a free app, TiltMeter on an Apple iPhone. This was an intra-rater and inter-rater reliability study. Two raters (novice and experienced) conducted the measurements in both a bent knee and straight leg position to determine the intra-rater and inter-rater reliability. Concurrent validity was also established. Allied health practitioners were recruited as participants from the workplace. A preconditioning stretch was conducted and the ankle range of motion was established with the weight bearing lunge test position with firstly the leg straight and secondly with the knee bent. The measurement device and each participant were randomised during measurement. The intra-rater reliability and inter-rater reliability for the devices and in both positions were all over ICC 0.8 except for one intra-rater measure (Digital inclinometer, novice, ICC 0.65). The inter-rater reliability between the digital inclinometer and the tilmeter was near perfect, ICC 0.96 (CI: 0.898-0.983); Concurrent validity ICC between the two devices was 0.83 (CI: -0.740 to 0.445). The use of the Tiltmeter app on the iPhone is a reliable and inexpensive tool to measure the available ankle range of motion. Health practitioners should use caution in applying these findings to other smart phone equipment if surface areas are not comparable. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  11. Antitumor activity and systemic effects of PVM/MA-shelled selol nanocapsules in lung adenocarcinoma-bearing mice

    NASA Astrophysics Data System (ADS)

    de Souza, Ludmilla Regina; Alexandre Muehlmann, Luis; Carneiro Matos, Lívia; Simón-Vázquez, Rosana; Guerreiro Marques Lacava, Zulmira; Maurício Batista De-Paula, Alfredo; Mosiniewicz-Szablewska, Ewa; Suchocki, Piotr; César Morais, Paulo; González-Fernández, África; Nair Báo, Sônia; Bentes Azevedo, Ricardo

    2015-12-01

    Selol is a semi-synthetic compound containing selenite that is effective against cancerous cells and safer for clinical applications in comparison with other inorganic forms of selenite. Recently, we have developed a formulation of poly(methyl vinyl ether-co-maleic anhydride)-shelled selol nanocapsules (SPN), which reduced the proliferative activity of lung adenocarcinoma cells and presented little deleterious effects on normal cells in in vitro studies. In this study, we report on the antitumor activity and systemic effects induced by this formulation in chemically induced lung adenocarcinoma-bearing mice. The in vivo antitumor activity of the SPN was verified by macroscopic quantification, immunohistochemistry and morphological analyses. Toxicity analyses were performed by evaluations of the kidney, liver, and spleen; analyses of hemogram and plasma levels of alanine aminotransferase, aspartate transaminase, urea, and creatinine; and DNA fragmentation and cell cycle activity of the bone marrow cells. Furthermore, we investigated the potential of the SPN formulation to cause hemolysis, activate the complement system, provoke an inflammatory response and change the conformation of the plasma proteins. Our results showed that the SPN reduced the area of the surface tumor nodules but not the total number of tumor nodules. The biochemical and hematological findings were suggestive of the low systemic toxicity of the SPN formulation. The surface properties of the selol nanocapsules point to characteristics that are consistent with the treatment of the tumors in vivo: low hemolytic activity, weak inflammatory reaction with no activation of the complement system, and mild or absent conformational changes of the plasma proteins. In conclusion, this report suggests that the SPN formulation investigated herein exhibits anti-tumoral effects against lung adenocarcinoma in vivo and is associated with low systemic toxicity and high biocompatibility.

  12. MicroRNA expression profiles of granulocytic myeloid‑derived suppressor cells from mice bearing Lewis lung carcinoma.

    PubMed

    Jiang, Jingwei; Gao, Qingmin; Wang, Tian; Lin, Hao; Zhan, Qiong; Chu, Zhaohui; Huang, Ruofan; Zhou, Xinli; Liang, Xiaohua; Guo, Weijian

    2016-11-01

    Myeloid-derived suppressor cells (MDSCs) are a group of heterogeneous myeloid cells that can suppress antitumor immunity. MDSCs are divided into granulocytic (G‑MDSCs) and monocytic subsets. In the present study, the microRNA profiles of the G‑MDSCs were determined and the differential expression of microRNAs between G‑MDSCs from tumor‑bearing mice and tumor‑free mice was examined. The number of G‑MDSCs in spleens of Lewis lung carcinoma (LLC)‑bearing mice was ~6‑fold higher than in spleens of normal mice (13.54±1.74% vs. 2.14±1.44%; P<0.01) and G‑MDSCs account for about 72.9% of all MDSCs. The microRNA (miRNA) profiles of the G‑MDSCs from spleen of LLC‑bearing mice were obtained using a microRNA microarray and compared with their counterparts from spleens of tumor‑free mice. A total of 43 miRNAs with >1.3‑fold increased or decreased change were differentially expressed between the experimental and control group mice. The levels of nine of these differentially expressed miRNAs, miRNA‑468 (miR‑486), miR‑192, miR‑128, miR‑125a, miR‑149, miR‑27a, miR‑125b, miR‑350 and miR‑328, were also analyzed by RT‑qPCR to validate the microarray data. The concordance rate between the results tested by the two methods was 88.9%. Bioinformatics analyses revealed that these miRNAs may act on various target genes, including Adar, Pik3r1, Rybp and Rabgap1, to regulate the survival, differentiation and the function of tumor‑induced granulocytic MDSCs. The results revealed microRNAs and potential targets that may be vital for regulating survival, differentiation and function of G‑MDSCs induced by LLC. Further investigation should be performed to clarify the roles of these microRNAs in regulating LLC‑induced granulocytic MDSCs and the target genes that mediate their functions.

  13. MicroRNA expression profiles of granulocytic myeloid-derived suppressor cells from mice bearing Lewis lung carcinoma

    PubMed Central

    Jiang, Jingwei; Gao, Qingmin; Wang, Tian; Lin, Hao; Zhan, Qiong; Chu, Zhaohui; Huang, Ruofan; Zhou, Xinli; Liang, Xiaohua; Guo, Weijian

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) are a group of heterogeneous myeloid cells that can suppress antitumor immunity. MDSCs are divided into granulocytic (G-MDSCs) and monocytic subsets. In the present study, the microRNA profiles of the G-MDSCs were determined and the differential expression of microRNAs between G-MDSCs from tumor-bearing mice and tumor-free mice was examined. The number of G-MDSCs in spleens of Lewis lung carcinoma (LLC)-bearing mice was ~6-fold higher than in spleens of normal mice (13.54±1.74% vs. 2.14±1.44%; P<0.01) and G-MDSCs account for about 72.9% of all MDSCs. The microRNA (miRNA) profiles of the G-MDSCs from spleen of LLC-bearing mice were obtained using a microRNA microarray and compared with their counterparts from spleens of tumor-free mice. A total of 43 miRNAs with >1.3-fold increased or decreased change were differentially expressed between the experimental and control group mice. The levels of nine of these differentially expressed miRNAs, miRNA-468 (miR-486), miR-192, miR-128, miR-125a, miR-149, miR-27a, miR-125b, miR-350 and miR-328, were also analyzed by RT-qPCR to validate the microarray data. The concordance rate between the results tested by the two methods was 88.9%. Bioinformatics analyses revealed that these miRNAs may act on various target genes, including Adar, Pik3r1, Rybp and Rabgap1, to regulate the survival, differentiation and the function of tumor-induced granulocytic MDSCs. The results revealed microRNAs and potential targets that may be vital for regulating survival, differentiation and function of G-MDSCs induced by LLC. Further investigation should be performed to clarify the roles of these microRNAs in regulating LLC-induced granulocytic MDSCs and the target genes that mediate their functions. PMID:27748875

  14. Combination treatment with oncolytic Vaccinia virus and cyclophosphamide results in synergistic antitumor effects in human lung adenocarcinoma bearing mice

    PubMed Central

    2014-01-01

    Background The capacity of the recombinant Vaccinia virus GLV-1h68 as a single agent to efficiently treat different human or canine cancers has been shown in several preclinical studies. Currently, its human safety and efficacy are investigated in phase I/II clinical trials. In this study we set out to evaluate the oncolytic activity of GLV-1h68 in the human lung adenocarcinoma cell line PC14PE6-RFP in cell cultures and analyzed the antitumor potency of a combined treatment strategy consisting of GLV-1h68 and cyclophosphamide (CPA) in a mouse model of PC14PE6-RFP lung adenocarcinoma. Methods PC14PE6-RFP cells were treated in cell culture with GLV-1h68. Viral replication and cell survival were determined by plaque assays and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, respectively. Subcutaneously implanted PC14PE6-RFP xenografts were treated by systemic injection of GLV-1h68, CPA or a combination of both. Tumor growth and viral biodistribution were monitored and immune-related antigen profiling of tumor lysates was performed. Results GLV-1h68 efficiently infected, replicated in and lysed human PC14PE6-RFP cells in cell cultures. PC14PE6-RFP tumors were efficiently colonized by GLV-1h68 leading to much delayed tumor growth in PC14PE6-RFP tumor-bearing nude mice. Combination treatment with GLV-1h68 and CPA significantly improved the antitumor efficacy of GLV-1h68 and led to an increased viral distribution within the tumors. Pro-inflammatory cytokines and chemokines were distinctly elevated in tumors of GLV-1h68-treated mice. Factors expressed by endothelial cells or present in the blood were decreased after combination treatment. A complete loss in the hemorrhagic phenotype of the PC14PE6-RFP tumors and a decrease in the number of blood vessels after combination treatment could be observed. Conclusions CPA and GLV-1h68 have synergistic antitumor effects on PC14PE6-RFP xenografts. We strongly suppose that in the PC14PE6-RFP model the

  15. [Immunoscintigraphy of anti-type IV collagenase monoclonal antibody in nude mice bearing human lung cancer xenograft].

    PubMed

    Dai, Yao; Jia, Bing; Wang, Fan; Du, Jin; Shang, Bo-Yang; Zhen, Yong-Su

    2003-12-01

    Matrix metalloproteinases (MMPs)play the important role in many steps of tumor growth and metastasis. Type IV collagenase, which is a key member of MMPs family, has been viewed as a promising target in tumor study. The aim of this study was to evaluate the tumor-specific distribution of the anti-type IV collagenase monoclonal antibody (mAb) 3G11 by radioimaging in tumor-bearing nude mice. MAb 3G11 purified by affinity chromatography was labeled with either 131- or 125- iodide by the Iodogen method. Immunoreactivity of mAb 3G11 was determined by ELISA. (131)I-labeled 3G11 was incubated in three different media at 37 Celsius degree and its in vitro stability was tested. Normal BALB/c mice were injected intravenously with 388.5 kBq per mouse of (125)I-labeled 3G11 to explore the pharmacokinetic patterns. The scintigraphic images of human lung carcinoma PG xenografts grown subcutaneously in BALB/c nude mice were made after intravenously administrating of 6.44 MBq per mouse of (131)I-labeled 3G11. MAb 3G11 was more than 98% in purity via affinity purification. The immunoreactivity of mAb 3G11 decreased by approximately 10%-20% after cold iodination. Patterns of blood clearance of mAb 3G11 was defined as two-compartment model, with T(1/2alpha) and T(1/2beta) calculated to be 7.2 h and 345.2 h, respectively. (131)I-labeled 3G11 was almost stable in vitro for 72 h. A clear image of the xenografted tumor was obtained at 72 h, and it further improved at 120 h. MAb 3G11 showed high specificity and affinity with tumor tissue through scintiscanning.

  16. Tissue distribution of 2-methoxyestradiol nanosuspension in rats and its antitumor activity in C57BL/6 mice bearing lewis lung carcinoma.

    PubMed

    Shen, Guopeng; Wang, Qingyu; Zhang, Qingqing; Sun, Huibin; Zhao, Ya; Zhang, Zhenzhong; Du, Bin

    2012-01-01

    The purpose of the present study was to evaluate the tissue distribution and antitumor activity of 2-methoxyestradiol (2-ME) nanosuspension compared with 2-ME solution both in vitro and in vivo. 2-ME nanosuspension was made by nanoprecipitation-high-frequency ultrasonication method with the particle size of 168.4 ± 3.2 nm and the zeta potential of -29.79 ± 1.89 mV. The overall targeting efficiency (TE(Q)) of 2-ME nanosuspension was improved from 28.71 to 51.95% in the lung of rats. MTT assay showed that 2-ME nanosuspension could significantly enhance the in vitro cytotoxicity against lewis lung carcinoma (LLC) cells compared with the 2-ME solution, the IC(50) at 72 h was reduced from 6.35 µM for 2-ME solution to 3.56 µM for 2-ME nanosuspension. The antitumor activity in vivo was investigated in C57BL/6 mice bearing LLC, and the results indicated that 2-ME nanosuspension not only exhibited significant suppression of the tumor growth when compared with that of positive group or cyclophosphamide group at the same dose, but also enhanced the spleen indices. Overall, 2-ME nanosuspension could mainly deliver the drug to lungs and made the drug accumulate in the lungs, so 2-ME nanosuspension has a possible lung cancer therapeutic potential.

  17. Curcumol induces apoptosis in SPC-A-1 human lung adenocarcinoma cells and displays anti-neoplastic effects in tumor bearing mice.

    PubMed

    Tang, Qi-Ling; Guo, Ji-Quan; Wang, Qi-You; Lin, Hai-Shu; Yang, Zhou-Ping; Peng, Tong; Pan, Xue-Diao; Liu, Bing; Wang, Su-Jun; Zang, Lin-Quan

    2015-01-01

    Curcumol is a sesquiterpene originally isolated from curcuma rhizomes, a component of herbal remedies commonly used in oriental medicine. Its beneficial pharmacological activities have attract significant interest recently. In this study, anti-cancer activity of curcumol was examined with both in vitro and in vivo models. It was found that curcumol exhibited time- and concentration-dependent anti-proliferative effects in SPC-A-1 human lung adenocarcinoma cells with cell cycle arrest in the G0/G1 phase while apoptosis-induction was also confirmed with flow cytometry and morphological analyses. Interestingly, curcumol did not display growth inhibition in MRC-5 human embryonic lung fibroblasts, suggesting the anti-proliferative effects of curcumol were specific to cancer cells. Anti-neoplastic effects of curcumol were also confirmed in tumor bearing mice. Curcumol (60 mg/kg daily) significantly reduced tumor size without causing notable toxicity. In conclusion, curcumol appears a favorable anti-cancer candidate for further development.

  18. Green tea and its major components ameliorate immune dysfunction in mice bearing Lewis lung carcinoma and treated with the carcinogen NNK.

    PubMed

    Zhu, M; Gong, Y; Yang, Z; Ge, G; Han, C; Chen, J

    1999-01-01

    The protective effects of tea and/or its components on dysfunction of immune functions during tumor growth and carcinogenesis in mice were studied using two experimental models: C57/BL6J mice transplanted with Lewis lung carcinoma (LLC) and Kunming mice treated with a single dose of 4-(methylnitrosamino-)-1-(3-pyridyl)-1-butanone (NNK). In C57/BL6J mice bearing LLC, the weight of the thymus decreased, the proportion of CD4(+)-positive T lymphocytes and the ratio of CD4+ to CD8+ decreased, luminol-enhanced chemiluminescence of white blood cells in peripheral blood stimulated by zymosan increased, and plaque-forming cells (PFC) decreased. However, in LLC-bearing mice given green tea as drinking water, all immune functions were improved, along with inhibition of tumor growth. In Kunming mice treated with NNK, during the four weeks of observation, their immunologic indicators, such as phagocytosis of macrophages in the abdominal cavity, luminol-enhanced chemiluminescence of white blood cells, plaque-forming cells, and delayed-type hypersensitivity, increased or decreased to various extents compared with normal controls. However, these changes were significantly prevented in the mice given green tea, mixed tea, or tea polyphenol as drinking water. In conclusion, tea and its components ameliorated immune dysfunction in mice bearing LLC or treated with the carcinogen NNK.

  19. Procoagulant, Tissue Factor-Bearing Microparticles in Bronchoalveolar Lavage of Interstitial Lung Disease Patients: An Observational Study

    PubMed Central

    Tavanti, Laura; Armani, Chiara; Noce, Concettina; Falaschi, Fabio; Bartoli, Maria Laura; Martino, Federica; Palla, Antonio; Celi, Alessandro; Paggiaro, Pierluigi

    2014-01-01

    Coagulation factor Xa appears involved in the pathogenesis of pulmonary fibrosis. Through its interaction with protease activated receptor-1, this protease signals myofibroblast differentiation in lung fibroblasts. Although fibrogenic stimuli induce factor X synthesis by alveolar cells, the mechanisms of local posttranslational factor X activation are not fully understood. Cell-derived microparticles are submicron vesicles involved in different physiological processes, including blood coagulation; they potentially activate factor X due to the exposure on their outer membrane of both phosphatidylserine and tissue factor. We postulated a role for procoagulant microparticles in the pathogenesis of interstitial lung diseases. Nineteen patients with interstitial lung diseases and 11 controls were studied. All subjects underwent bronchoalveolar lavage; interstitial lung disease patients also underwent pulmonary function tests and high resolution CT scan. Microparticles were enumerated in the bronchoalveolar lavage fluid with a solid-phase assay based on thrombin generation. Microparticles were also tested for tissue factor activity. In vitro shedding of microparticles upon incubation with H2O2 was assessed in the human alveolar cell line, A549 and in normal bronchial epithelial cells. Tissue factor synthesis was quantitated by real-time PCR. Total microparticle number and microparticle-associated tissue factor activity were increased in interstitial lung disease patients compared to controls (84±8 vs. 39±3 nM phosphatidylserine; 293±37 vs. 105±21 arbitrary units of tissue factor activity; mean±SEM; p<.05 for both comparisons). Microparticle-bound tissue factor activity was inversely correlated with lung function as assessed by both diffusion capacity and forced vital capacity (r2 = .27 and .31, respectively; p<.05 for both correlations). Exposure of lung epithelial cells to H2O2 caused an increase in microparticle-bound tissue factor without affecting tissue

  20. Non-extended cryoablation could be a new strategy in lung cancer management: An experiment on green fluorescent protein-labeled Lewis lung cancer-bearing mice.

    PubMed

    Zhou, Tian; Chen, Yujia; Li, Linyi; Qi, Hui; Shi, Jinping; Lu, Chongyi; Jiang, Sida; Geng, Tan; Yang, Meng; Li, Quanwang; Hu, Kaiwen

    2015-08-01

    Modern cryoablation has been performed in solid tumor management for more than two decades. Following the surgical spirits, it seems natural to pursue radical procedures in clinical practice, which results in unnecessary adverse effects. The attempt to use non-extended procedure made some marked achievements in practice but was criticized severely, because it was supposed to induce residual tumors, which would trigger the rapid development of cancer. Oncologists favored this procedure, however, claiming that non-extended cryoablation let lung cancer patients have higher quality of lives and longer survivals, in light of clinical observations. Therefore, this study was conducted trying to solve this controversy. In this study, fifty female C57BL/6J mice were grafted green fluorescent protein (GFP)-labeled Lewis lung cancer and randomized into two groups. The bidirectional diameters and fluorescence intensity of tumors, and the body weight of mice were recorded. Two weeks after the intervention, tumor volumes increased 20.95% in the cryoablation group, significantly different from that in the control group; the fluorescence intensity decreased 49.85% in the cryoablation group but increased 125.07% in the control group. Lung metastases could be observed in only 20% of mice in the cryosurgery group, contrasted to 64% in the control group. The non-extended lung cancer cryoablation does induce marginal tumor residuals, but will not trigger rapid tumor development. Inversely, the residual tumor cells are severely struck and the metastases are suppressed after the intervention. It could be a new strategy in lung cancer management, even for patients not in early stage.

  1. Analysis of volatile organic compounds released from human lung cancer cells and from the urine of tumor-bearing mice

    PubMed Central

    2012-01-01

    Backgrounds A potential strategy for the diagnosis of lung cancer is to exploit the distinct metabolic signature of this disease by way of biomarkers found in different sample types. In this study, we investigated whether specific volatile organic compounds (VOCs) could be detected in the culture medium of the lung cancer cell line A549 in addition to the urine of mice implanted with A549 cells. Results Several VOCs were found at significantly increased or decreased concentrations in the headspace of the A549 cell culture medium as compared with the culture medium of two normal lung cell lines. We also analyzed the urine of mice implanted with A549 cells and several VOCs were also found to be significantly increased or decreased relative to urine obtained from control mice. It was also revealed that seven VOCs were found at increased concentrations in both sample types. These compounds were found to be dimethyl succinate, 2-pentanone, phenol, 2-methylpyrazine, 2-hexanone, 2-butanone and acetophenone. Conclusions Both sample types produce distinct biomarker profiles, and VOCs have potential to distinguish between true- and false-positive screens for lung cancer. PMID:22364569

  2. Effect of cisplatin and cobalt chloride on antioxidant enzymes in the livers of Lewis lung carcinoma-bearing mice: protective role of heme oxygenase.

    PubMed

    Christova, Tania Y; Gorneva, Galina A; Taxirov, Svetoslav I; Duridanova, Dessislava B; Setchenska, Milka S

    2003-03-03

    Changes in the activities of antioxidant enzymes superoxide dismutase, catalase (CAT), glutathione peroxidase and heme oxygenase (HO) and changes in lipid peroxidation and reduced glutathione (GSH) levels were measured in the livers of control and Lewis lung carcinoma (LLC)-bearing mice 24 h after a single injection of cisplatin or CoCl(2). Treatment with cisplatin induced the same degree of lipid peroxidation and GSH depletion as did CoCl(2) but the antioxidant enzymes were differently involved in cisplatin- and cobalt-induced oxidative stress responses. In cobalt-treated mice the activities of these enzymes were either inhibited or not changed significantly and only the HO activity was increased (5-fold) as a main protective enzyme. In cisplatin-treated animals the antioxidant enzymes were activated but the enhancement of HO and CAT was greater in LLC-inoculated mice. It is suggested that these two enzymes represent the protective response against cisplatin toxicity in the livers of tumor-bearing animals.

  3. Effects of Feijining Decoction on vascular endothelial growth factor protein expression and changes of T cell subsets in Lewis lung carcinoma-bearing mice.

    PubMed

    Zhou, Lijiang; Pan, Yuzhen; Xing, Yuqing; Gao, Hong; Xie, Xiaodong; Yin, Dongfeng

    2015-05-01

    Angiogenesis is crucial for cancer growth and metastasis. T cells are also key members of the adaptive immunity against tumorigenesis. The aim of the present study was to observe the effects of Feijining Decoction (FJND) on vascular endothelial growth factor (VEGF) protein expression and T cell subsets [cluster of differentiation 4(+)(CD4(+)) and CD8(+) T lymphocyte] in Lewis lung carcinoma (LLC)-bearing mice. C57BL/6J mice were subcutaneously implanted with LLC cells. Forty carcinoma-bearing mice were randomly assigned to four groups (10 animals/group). The control group (CG) were the untreated group, the cisplatinum (DDP) group (DG) mice were treated with DDP, the FJND group (FG) were treated with FJND and the FJND + DDP group (FDG) were treated with FJND and DDP. Western blot and flow cytometry were used to evaluate the VEGF protein expression of tumor tissue and T cell subsets of the spleen. Spontaneous activity in 5 min was observed by the photoelectric counting method. DDP + FJND (FDG group) markedly inhibited tumor growth compared to the DG mice. The protein expression of VEGF was significantly downregulated in the carcinoma of FG mice compared to CG mice. VEGF protein expression was significantly reduced in FDG compared to DG mice. In the FG mice, the splenic CD4(+) and CD4(+)/CD8(+) cells were significantly increased compared to the CG mice, and the splenic CD4(+) cells in the FDG mice were significantly increased compared to the DG group. In conclusion, FJND can inhibit tumor growth by downregulating VEGF protein expression and improving the immune function.

  4. Improved antiangiogenic and antitumour activity of the combination of the natural flavonoid fisetin and cyclophosphamide in Lewis lung carcinoma-bearing mice

    PubMed Central

    Touil, Yasmine S.; Seguin, Johanne; Scherman, Daniel; Chabot, Guy G.

    2011-01-01

    Purpose The natural flavonoid fisetin was recently identified as a lead compound that stabilizes endothelial cell microtubules. In this study we investigated the antiproliferative and antiangiogenic properties of fisetin in vitro and in vivo. Methods Fisetin cytotoxicity was evaluated using Lewis lung carcinoma cells (LLC), endothelial cells and NIH 3T3 cells. Endothelial cell (EC) migration and capillary-like structure formation were evaluated using EAhy 926 cells. In vivo tumour growth inhibition studies were performed using LLC bearing mice treated with fisetin and/or cyclophosphamide (CPA). Results The fisetin IC50 was 59 μM for LLC and 77 μM for EC cells, compared to 210 μM for normal NIH 3T3 cells (24 h). Fisetin inhibited EC migration and capillary-like structure formation at non-cytotoxic concentrations (22–44 μM). In mice, fisetin inhibited angiogenesis assessed using the Matrigel plug assay. In LLC bearing mice, fisetin produced a 67% tumour growth inhibition (223 mg/kg, intraperitoneal), similar to the 66% produced by low dose CPA (30 mg/kg, subcutaneous). When fisetin and CPA were combined, however, a marked improvement in antitumour activity was observed (92% tumour growth inhibition), with low systemic toxicity. Tumour histology showed decreased microvessel density with either fisetin or CPA alone, and a dramatic decrease after the fisetin/CPA combination. Conclusions We have shown that fisetin not only displays in vitro and in vivo antiangiogenic properties, but that it can also markedly improve the in vivo antitumour effect of CPA. We propose that this drug combination associating a non-toxic dietary flavonoid with a cytotoxic agent could advantageously be used in the treatment of solid tumours. PMID:21069336

  5. Effects of Feijining Decoction on vascular endothelial growth factor protein expression and changes of T cell subsets in Lewis lung carcinoma-bearing mice

    PubMed Central

    ZHOU, LIJIANG; PAN, YUZHEN; XING, YUQING; GAO, HONG; XIE, XIAODONG; YIN, DONGFENG

    2015-01-01

    Angiogenesis is crucial for cancer growth and metastasis. T cells are also key members of the adaptive immunity against tumorigenesis. The aim of the present study was to observe the effects of Feijining Decoction (FJND) on vascular endothelial growth factor (VEGF) protein expression and T cell subsets [cluster of differentiation 4+(CD4+) and CD8+ T lymphocyte] in Lewis lung carcinoma (LLC)-bearing mice. C57BL/6J mice were subcutaneously implanted with LLC cells. Forty carcinoma-bearing mice were randomly assigned to four groups (10 animals/group). The control group (CG) were the untreated group, the cisplatinum (DDP) group (DG) mice were treated with DDP, the FJND group (FG) were treated with FJND and the FJND + DDP group (FDG) were treated with FJND and DDP. Western blot and flow cytometry were used to evaluate the VEGF protein expression of tumor tissue and T cell subsets of the spleen. Spontaneous activity in 5 min was observed by the photoelectric counting method. DDP + FJND (FDG group) markedly inhibited tumor growth compared to the DG mice. The protein expression of VEGF was significantly downregulated in the carcinoma of FG mice compared to CG mice. VEGF protein expression was significantly reduced in FDG compared to DG mice. In the FG mice, the splenic CD4+ and CD4+/CD8+ cells were significantly increased compared to the CG mice, and the splenic CD4+ cells in the FDG mice were significantly increased compared to the DG group. In conclusion, FJND can inhibit tumor growth by downregulating VEGF protein expression and improving the immune function. PMID:26137245

  6. Intra-rater reliability and agreement of various methods of measurement to assess dorsiflexion in the Weight Bearing Dorsiflexion Lunge Test (WBLT) among female athletes.

    PubMed

    Langarika-Rocafort, Argia; Emparanza, José Ignacio; Aramendi, José F; Castellano, Julen; Calleja-González, Julio

    2017-01-01

    To examine the intra-observer reliability and agreement between five methods of measurement for dorsiflexion during Weight Bearing Dorsiflexion Lunge Test and to assess the degree of agreement between three methods in female athletes. Repeated measurements study design. Volleyball club. Twenty-five volleyball players. Dorsiflexion was evaluated using five methods: heel-wall distance, first toe-wall distance, inclinometer at tibia, inclinometer at Achilles tendon and the dorsiflexion angle obtained by a simple trigonometric function. For the statistical analysis, agreement was studied using the Bland-Altman method, the Standard Error of Measurement and the Minimum Detectable Change. Reliability analysis was performed using the Intraclass Correlation Coefficient. Measurement methods using the inclinometer had more than 6° of measurement error. The angle calculated by trigonometric function had 3.28° error. The reliability of inclinometer based methods had ICC values < 0.90. Distance based methods and trigonometric angle measurement had an ICC values > 0.90. Concerning the agreement between methods, there was from 1.93° to 14.42° bias, and from 4.24° to 7.96° random error. To assess DF angle in WBLT, the angle calculated by a trigonometric function is the most repeatable method. The methods of measurement cannot be used interchangeably. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Evidence for selection against human lung cancers bearing p53 missense mutations which occur within the HLA A*0201 peptide consensus motif.

    PubMed

    Wiedenfeld, E A; Fernandez-Viña, M; Berzofsky, J A; Carbone, D P

    1994-03-01

    Short peptide fragments of intracellular proteins that fit a defined sequence motif bind to the most common human major histocompatibility complex class I molecule, HLA A*0201, and mediate killing by cytotoxic T-cells [D.F. Hunt et al., Science (Washington DC), 255: 1261-1263, 1992; K. Falk et al., Nature (Lond.), 351: 290-296, 1991]. The existence of such a motif allows prediction of whether novel peptides derived from mutant oncoporteins might be presented on the surface of cancer cells bearing that HLA allele. Clinical cancer might develop only when these mutations occur outside a major histocompatibility complex binding motif or in those cells that acquire defects in antigen presentation. Here, we find that missense mutations of p53 from a variety of tumors fall within the HLA A*0201 motif less often than would be expected if the location of mutations and motifs were independent. When we analyzed the HLA subtype of lung cancer cell lines with known p53 missense mutations, we found that all of the mutant oncopeptides predicted to be presentable by HLA A*0201 came from tumors that either did not carry the A*0201 allele or had lost that allele in the process of tumorigenesis. Presentation of mutant oncogene peptides on class I major histocompatibility complex might thus represent a physiologically significant selection pressure in the development of human cancer.

  8. Bearing system

    DOEpatents

    Kapich, Davorin D.

    1987-01-01

    A bearing system includes backup bearings for supporting a rotating shaft upon failure of primary bearings. In the preferred embodiment, the backup bearings are rolling element bearings having their rolling elements disposed out of contact with their associated respective inner races during normal functioning of the primary bearings. Displacement detection sensors are provided for detecting displacement of the shaft upon failure of the primary bearings. Upon detection of the failure of the primary bearings, the rolling elements and inner races of the backup bearings are brought into mutual contact by axial displacement of the shaft.

  9. Study of Bioreductive Anticancer Agent RH-1-Induced Signals Leading the Wild-Type p53-Bearing Lung Cancer A549 Cells to Apoptosis.

    PubMed

    Stulpinas, Aurimas; Imbrasaitė, Aušra; Krestnikova, Natalija; Šarlauskas, Jonas; Čėnas, Narimantas; Kalvelytė, Audronė Valerija

    2016-01-19

    Aziridinylquinone RH-1 (2,5-diaziridinyl-3-hydroxymethyl-6-methyl-cyclohexa-2,5-diene-1,4-dione) is a potential anticancer agent. RH-1 action is associated with quinone oxidoreductase (NQO1) which reduces this diaziridinylbenzoquinone into DNA-alkylating hydroquinone and is overexpressed in many tumors. Another suggested mechanism of RH-1 toxicity is the formation of reactive oxygen species (ROS) arising from its redox cycling. In order to improve anticancer action of this and similar antitumor quinones, we investigated the involvement of different signaling molecules in cytotoxicity induced by RH-1 by using wild-type tumor suppressor p53 bearing nonsmall cell lung carcinoma A549 cells as a model. Gradual and prolonged increase of mitogen-activated protein kinases (MAPK) ERK, P38, and JNK phosphorylation was observed during 24-h RH-1 treatment. In parallel, activation of DNA damage-sensing ATM kinase, upregulation, and phosphorylation of TP53 (human p53) took place. Inhibition studies revealed that RH-1-induced A549 apoptosis involved the NQO1-ATM-p53 signaling pathway and ROS generation. TP53 participated in ROS- and DNA damage-induced cell death differently. Moreover, MAP kinase JNK was another TP53 activator and death inducer in A549 cells. At the same time, rapid and prolonged activation of AKT kinase during RH-1 treatment was found, and it proved to be antiapoptotic kinase in our model system. Therefore, we identified that different and opposite cell death regulating signaling pathways, which may counteract one another, are induced in cancer cells during chemotherapeutic RH-1 treatment.

  10. UPLC-MS method for quantification of pterostilbene and its application to comparative study of bioavailability and tissue distribution in normal and Lewis lung carcinoma bearing mice.

    PubMed

    Deng, Li; Li, Yongzhi; Zhang, Xinshi; Chen, Bo; Deng, Yulin; Li, Yujuan

    2015-10-10

    A UPLC-MS method was developed for determination of pterostilbene (PTS) in plasma and tissues of mice. PTS was separated on Agilent Zorbax XDB-C18 column (50 × 2.1 mm, 1.8 μm) with gradient mobile phase at the flow rate of 0.2 ml/min. The detection was performed by negative ion electrospray ionization in multiple reaction monitoring mode. The linear calibration curve of PTS in mouse plasma and tissues ranged from 1.0 to 5000 and 0.50 to 500 ng/ml (r(2)>0.9979), respectively, with lowest limits of quantification (LLOQ) were between 0.5 and 2.0 ng/ml, respectively. The accuracy and precision of the assay were satisfactory. The validated method was applied to the study of bioavailability and tissue distribution of PTS in normal and Lewis lung carcinoma (LLC) bearing mice. The bioavailability of PTS (dose 14, 28 and 56 mg/kg) in normal mice were 11.9%, 13.9% and 26.4%, respectively; and the maximum level (82.1 ± 14.2 μg/g) was found in stomach (dose 28 mg/kg). The bioavailability, peak concentration (Cmax), time to peak concentration (Tmax) of PTS in LLC mice was increased compared with normal mice. The results indicated the UPLC-MS method is reliable and bioavailability and tissue distribution of PTS in normal and LLC mice were dramatically different. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. THRUST BEARING

    DOEpatents

    Heller, P.R.

    1958-09-16

    A thrust bearing suitable for use with a rotor or blower that is to rotate about a vertical axis is descrihed. A centrifagal jack is provided so thnt the device may opernte on one hearing at starting and lower speeds, and transfer the load to another bearing at higher speeds. A low viscosity fluid is used to lubricate the higher speed operation bearing, in connection with broad hearing -surfaces, the ability to withstand great loads, and a relatively high friction loss, as contraated to the lower speed operatio;n bearing which will withstand only light thrust loads but is sufficiently frictionfree to avoid bearing seizure during slow speed or startup operation. An axially aligned shaft pin provides the bearing surface for low rotational speeds, but at higher speed, weights operating against spring tension withdraw nthe shaft pin into the bearing proper and the rotor shaft comes in contact with the large bearing surfaces.

  12. Gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2003-01-01

    A gear bearing having a first gear and a second gear, each having a plurality of teeth. Each gear operates on two non-parallel surfaces of the opposing gear teeth to perform both gear and bearing functions simultaneously. The gears are moving at substantially the same speed at their contact points. The gears may be roller gear bearings or phase-shifted gear bearings, and may be arranged in a planet/sun system or used as a transmission.

  13. Journal bearing

    DOEpatents

    Menke, John R.; Boeker, Gilbert F.

    1976-05-11

    1. An improved journal bearing comprising in combination a non-rotatable cylindrical bearing member having a first bearing surface, a rotatable cylindrical bearing member having a confronting second bearing surface having a plurality of bearing elements, a source of lubricant adjacent said bearing elements for supplying lubricant thereto, each bearing element consisting of a pair of elongated relatively shallowly depressed surfaces lying in a cylindrical surface co-axial with the non-depressed surface and diverging from one another in the direction of rotation and obliquely arranged with respect to the axis of rotation of said rotatable member to cause a flow of lubricant longitudinally along said depressed surfaces from their distal ends toward their proximal ends as said bearing members are rotated relative to one another, each depressed surface subtending a radial angle of less than 360.degree., and means for rotating said rotatable bearing member to cause the lubricant to flow across and along said depressed surfaces, the flow of lubricant being impeded by the non-depressed portions of said second bearing surface to cause an increase in the lubricant pressure.

  14. GAS BEARING

    DOEpatents

    Skarstrom, C.W.

    1960-09-01

    A gas lubricated bearing for a rotating shaft is described. The assembly comprises a stationary collar having an annular member resiliently supported thereon. The collar and annular member are provided with cooperating gas passages arranged for admission of pressurized gas which supports and lubricates a bearing block fixed to the rotatable shaft. The resilient means for the annular member support the latter against movement away from the bearing block when the assembly is in operation.

  15. Grizzly bear

    USGS Publications Warehouse

    Schwartz, C.C.; Miller, S.D.; Haroldson, M.A.; Feldhamer, G.; Thompson, B.; Chapman, J.

    2003-01-01

    The grizzly bear inspires fear, awe, and respect in humans to a degree unmatched by any other North American wild mammal. Like other bear species, it can inflict serious injury and death on humans and sometimes does. Unlike the polar bear (Ursus maritimus) of the sparsely inhabited northern arctic, however, grizzly bears still live in areas visited by crowds of people, where presence of the grizzly remains physically real and emotionally dominant. A hike in the wilderness that includes grizzly bears is different from a stroll in a forest from which grizzly bears have been purged; nighttime conversations around the campfire and dreams in the tent reflect the presence of the great bear. Contributing to the aura of the grizzly bear is the mixture of myth and reality about its ferocity. unpredictable disposition, large size, strength, huge canines, long claws, keen senses, swiftness, and playfulness. They share characteristics with humans such as generalist life history strategies. extended periods of maternal care, and omnivorous diets. These factors capture the human imagination in ways distinct from other North American mammals. Precontact Native American legends reflected the same fascination with the grizzly bear as modern stories and legends (Rockwell 1991).

  16. Polar Bears

    USGS Publications Warehouse

    Amstrup, Steven C.; Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.

    2002-01-01

    Polar bears (Ursus maritimus) are hunted throughout most of their range. In addition to hunting polar bears of the Beaufort Sea region are exposed to mineral and petroleum extraction and related human activities such as shipping road-building, and seismic testing (Stirling 1990).Little was known at the start of this project about how polar bears move about in their environment, and although it was understood that many bears travel across political borders, the boundaries of populations had not been delineated (Amstrup 1986, Amstrup et al. 1986, Amstrup and DeMaster 1988, Garner et al. 1994, Amstrup 1995, Amstrup et al. 1995, Amstrup 2000).As human populations increase and demands for polar bears and other arctic resources escalate, managers must know the sizes and distributions of the polar bear populations. Resource managers also need reliable estimates of breeding rates, reproductive intervals, litter sizes, and survival of young and adults.Our objectives for this research were 1) to determine the seasonal and annual movements of polar bears in the Beaufort Sea, 2) to define the boundaries of the population(s) using this region, 3) to determine the size and status of the Beaufort Sea polar bear population, and 4) to establish reproduction and survival rates (Amstrup 2000).

  17. Polar Bear

    USGS Publications Warehouse

    Amstrup, S.D.; ,; Lentfer, J.W.

    1988-01-01

    Polar bears are long-lived, late-maturing carnivores that have relatively low rates of reproduction and natural mortality. Their populations are susceptible to disturbance from human activities, such as the exploration and development of mineral resources or hunting. Polar bear populations have been an important renewable resource available to coastal communities throughout the Arctic for thousands of years.

  18. Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    1996-01-01

    AVCON, Inc. produces advanced magnetic bearing systems for industrial use, offering a unique technological approach based on contract work done at Marshall Space Flight Center and Lewis Research Center. Designed for the turbopump of the Space Shuttle main engine, they are now used in applications such as electric power generation, petroleum refining, machine tool operation and natural gas pipelines. Magnetic bearings support moving machinery without physical contact; AVCON's homopolar approach is a hybrid of permanent and electromagnets which are one-third the weight, smaller and more power- efficient than previous magnetic bearings.

  19. Foil bearings

    NASA Astrophysics Data System (ADS)

    Elrod, David A.

    1993-11-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are: (1) rolling or sliding contact within the bearing has life-limiting consequences; and (2) REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contracts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exists for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. This report describes the first phase of a structural analysis of a bending-dominated, multileaf CFB. A brief discussion of CFB literature is followed by a description and results of the present analysis.

  20. Foil bearings

    NASA Technical Reports Server (NTRS)

    Elrod, David A.

    1993-01-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are: (1) rolling or sliding contact within the bearing has life-limiting consequences; and (2) REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contracts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exists for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. This report describes the first phase of a structural analysis of a bending-dominated, multileaf CFB. A brief discussion of CFB literature is followed by a description and results of the present analysis.

  1. Seismic bearing

    NASA Astrophysics Data System (ADS)

    Power, Dennis

    2009-05-01

    Textron Systems (Textron) has been using geophones for target detection for many years. This sensing capability was utilized for detection and classification purposes only. Recently Textron has been evaluating multiaxis geophones to calculate bearings and track targets more specifically personnel. This capability will not only aid the system in locating personnel in bearing space or cartesian space but also enhance detection and reduce false alarms. Textron has been involved in the testing and evaluation of several sensors at multiple sites. One of the challenges of calculating seismic bearing is an adequate signal to noise ratio. The sensor signal to noise ratio is a function of sensor coupling to the ground, seismic propagation and range to target. The goals of testing at multiple sites are to gain a good understanding of the maximum and minimum ranges for bearing and detection and to exploit that information to tailor sensor system emplacement to achieve desired performance. Test sites include 10A Site Devens, MA, McKenna Airfield Ft. Benning, GA and Yuma Proving Ground Yuma, AZ. Geophone sensors evaluated include a 28 Hz triax spike, a 15 Hz triax spike and a hybrid triax spike consisting of a 10 Hz vertical geophone and two 28 Hz horizontal geophones. The algorithm uses raw seismic data to calculate the bearings. All evaluated sensors have triaxial geophone configuration mounted to a spike housing/fixture. The suite of sensors also compares various types of geophones to evaluate benefits in lower bandwidth. The data products of these tests include raw geophone signals, seismic features, seismic bearings, seismic detection and GPS position truth data. The analyses produce Probability of Detection vs range, bearing accuracy vs range, and seismic feature level vs range. These analysis products are compared across test sites and sensor types.

  2. System for testing bearings

    NASA Technical Reports Server (NTRS)

    Gibson, John C. (Inventor)

    1993-01-01

    Disclosed here is a system for testing bearings wherein a pair of spaced bearings provides support for a shaft on which is mounted a bearing to be tested, this bearing being mounted in a bearing holder spaced from and in alignment with the pair of bearings. The bearing holder is provided with an annular collar positioned in an opening in the bearing holder for holding the bearing to be tested. A screw threaded through the bearing holder into engagement with the annular collar can be turned to force the collar radially out of alignment with the pair of bearings to apply a radial load to the bearing.

  3. CUSHIONED BEARING

    DOEpatents

    Rushing, F.C.

    1960-09-01

    A vibration damping device effective to dampen vibrations occurring at the several critical speeds encountered in the operation of a high-speed centrifuge is described. A self-centering bearing mechanism is used to protect both the centrifuge shaft and the damping mechanism. The damping mechanism comprises spaced-apant, movable, and stationary sleeve members arranged concentrically of a rotating shaft with a fluid maintained between the members. The movable sleeve member is connected to the shaft for radial movement therewith.

  4. Camshaft bearing arrangement

    SciTech Connect

    Aoi, K.; Ozawa, T.

    1986-06-10

    A bearing arrangement is described for the camshaft of an internal combustion engine or the like which camshaft is formed along its length in axial order with a first bearing surface, a first cam lobe, a second bearing surface, a second cam lobe, a third bearing surface, a third cam lobe and a fourth bearing surface, the improvement comprising first bearing means extending around substantially the full circumference of the first bearing surface and journaling the first bearing surface, second bearing means extending around substantially less than the circumference of the second bearing surface and journaling the second bearing surface, third bearing means extending around substantially less than the circumference of the third bearing surface and journaling the third bearing surface, and fourth bearing means extending around substantially the full circumference of the fourth bearing surface and journaling the first bearing surface.

  5. Tooling Converts Stock Bearings To Custom Bearings

    NASA Technical Reports Server (NTRS)

    Fleenor, E. N., Jr.

    1983-01-01

    Technique for reworking stock bearings saves time and produces helicopter-rotor bearings ground more precisely. Split tapered ring at one end of threaded bolt expands to hold inside of inner race bearing assembly; nut, at other end of bolt, adjusts amount of spring tension. Piece of hardware grasps bearing firmly without interfering with grinding operation. Operation produces bearing of higher quality than commercially available bearings.

  6. Advances In Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Fleming, David P.

    1994-01-01

    NASA technical memorandum reviews state of technology of magnetic bearings, focusing mainly on attractive bearings rather than repulsive, eddy-current, or Lorentz bearings. Attractive bearings offer greater load capacities and preferred for aerospace machinery.

  7. Fluid lubricated bearing construction

    DOEpatents

    Dunning, John R.; Boorse, Henry A.; Boeker, Gilbert F.

    1976-01-01

    1. A fluid lubricated thrust bearing assembly comprising, in combination, a first bearing member having a plain bearing surface, a second bearing member having a bearing surface confronting the bearing surface of said first bearing member and provided with at least one spiral groove extending inwardly from the periphery of said second bearing member, one of said bearing members having an axial fluid-tight well, a source of fluid lubricant adjacent to the periphery of said second bearing member, and means for relatively rotating said bearing members to cause said lubricant to be drawn through said groove and to flow between said bearing surfaces, whereby a sufficient pressure is built up between said bearing surfaces and in said well to tend to separate said bearing surfaces.

  8. Lung Transplant

    MedlinePlus

    Lung transplant Overview By Mayo Clinic Staff A lung transplant is a surgical procedure to replace a diseased or ... lung, usually from a deceased donor. A lung transplant is reserved for people who have tried other ...

  9. Lung surgery

    MedlinePlus

    ... lung tissue that is diseased or damaged from emphysema or bronchiectasis Remove blood or blood clots ( hemothorax ) ... Editorial team. Related MedlinePlus Health Topics Collapsed Lung Emphysema Lung Cancer Lung Diseases Pleural Disorders Browse the ...

  10. Lung Emergencies

    MedlinePlus

    ... Emergencies Cardiac Emergencies Eye Emergencies Lung Emergencies Surgeries Lung Emergencies People with Marfan syndrome can be at ... should be considered an emergency. Symptoms of sudden lung collapse (pneumothorax) Symptoms of a sudden lung collapse ...

  11. Lung Cancer

    MedlinePlus

    ... version of this page please turn Javascript on. Lung Cancer What is Lung Cancer? How Tumors Form The body is made ... button on your keyboard.) Two Major Types of Lung Cancer There are two major types of lung ...

  12. Passive magnetic bearing configurations

    DOEpatents

    Post, Richard F [Walnut Creek, CA

    2011-01-25

    A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.

  13. Restoration of bearings

    NASA Technical Reports Server (NTRS)

    Parker, R. J.; Zaretsky, E. V.; Hanau, H.

    1977-01-01

    Process consisting of grinding raceways to oversize but original quality condition and installing new oversize balls or bearings restores wornout ball and roller bearings to original quality, thereby doubling their operating life. Evaluations reveal process results in restoration of 90% of replaced bearings at less than 50% of new-bearing costs.

  14. Rolling-Element Bearings

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Anderson, W. J.

    1983-01-01

    Rolling element bearings are a precision, yet simple, machine element of great utility. A brief history of rolling element bearings is reviewed and the type of rolling element bearings, their geometry and kinematics, as well as the materials they are made from and the manufacturing processes they involve are described. Unloaded and unlubricated rolling element bearings, loaded but unlubricated rolling element bearings and loaded and lubricated rolling element bearings are considered. The recognition and understanding of elastohydrodynamic lubrication covered, represents one of the major development in rolling element bearings.

  15. Cryogenic foil bearing turbopumps

    NASA Technical Reports Server (NTRS)

    Gu, Alston L.

    1993-01-01

    Cryogenic foil bearing turbopumps offer high reliability and low cost. The fundamental cryogenic foil bearing technology has been validated in both liquid hydrogen and liquid oxygen. High load capacity, excellent rotor dynamics, and negligible bearing wear after over 100 starts and stops, and over many hours of testing, were observed in both fluids. An experimental liquid hydrogen foil bearing turbopump was also successfully demonstrated. The results indicate excellent stability, high reliability, wide throttle-ability, low bearing cooling flow, and two-phase bearing operability. A liquid oxygen foil bearing turbopump has been built and is being tested at NASA MSFC.

  16. Introduction to ball bearings

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1981-01-01

    The purpose of a ball bearing is to provide a relative positioning and rotational freedom while transmitting a load between two structures, usually a shaft and a housing. For high rotational speeds (e.g., in gyroscope ball bearings) the purpose can be expanded to include rotational freedom with practically no wear in the bearing. This condition can be achieved by separating the bearing parts with a coherent film of fluid known as an elastohydrodynamic film. This film can be maintained not only when the bearing carries the load on a shaft, but also when the bearing is preloaded to position the shaft to within micro- or nano-inch accuracy and stability. Background information on ball bearings is provided, different types of ball bearings and their geometry and kinematics are defined, bearing materials, manufacturing processes, and separators are discussed. It is assumed, for the purposes of analysis, that the bearing carries no load.

  17. High efficiency magnetic bearings

    NASA Technical Reports Server (NTRS)

    Studer, Philip A.; Jayaraman, Chaitanya P.; Anand, Davinder K.; Kirk, James A.

    1993-01-01

    Research activities concerning high efficiency permanent magnet plus electromagnet (PM/EM) pancake magnetic bearings at the University of Maryland are reported. A description of the construction and working of the magnetic bearing is provided. Next, parameters needed to describe the bearing are explained. Then, methods developed for the design and testing of magnetic bearings are summarized. Finally, a new magnetic bearing which allows active torque control in the off axes directions is discussed.

  18. Lung cancer

    SciTech Connect

    Aisner, J.

    1985-01-01

    This book contains 13 chapters. Some of the chapter titles are: The Pathology of Lung Cancer; Radiotherapy for Non-Small-Cell Cancer of the Lung; Chemotherapy for Non-Small-Cell Lung Cancer; Immunotherapy in the Management of Lung Cancer; Preoperative Staging and Surgery for Non-Small-Cell Lung Cancer; and Prognostic Factors in Lung Cancer.

  19. Investigating Science through Bears (and Teddy Bears).

    ERIC Educational Resources Information Center

    Smith, Karlene Ray

    1997-01-01

    Presents cooperative classroom projects using science as the initial basis for the study of bears. These projects may also involve other areas of the curriculum such as mathematics, art, and music. "Black Bear" activities include following a park ranger to study our National Parks and researching and building a full-sized brown bear…

  20. Investigating Science through Bears (and Teddy Bears).

    ERIC Educational Resources Information Center

    Smith, Karlene Ray

    1997-01-01

    Presents cooperative classroom projects using science as the initial basis for the study of bears. These projects may also involve other areas of the curriculum such as mathematics, art, and music. "Black Bear" activities include following a park ranger to study our National Parks and researching and building a full-sized brown bear…

  1. Experiments with needle bearings

    NASA Technical Reports Server (NTRS)

    Ferretti, Pericle

    1933-01-01

    Experiments and results are presented in testing needle bearings, especially in comparison with roller bearings. Reduction in coefficient of friction is discussed as well as experimental methods and recording devices.

  2. Mechanical spin bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1998-01-01

    A spin bearing assembly including, a pair of mutually opposing complementary bearing support members having mutually spaced apart bearing support surfaces which may be, for example, bearing races and a set of spin bearings located therebetween. Each spin bearing includes a pair of end faces, a central rotational axis passing through the end faces, a waist region substantially mid-way between the end faces and having a first thickness dimension, and discrete side surface regions located between the waist region and the end faces and having a second thickness dimension different from the first thickness dimension of the waist region and wherein the side surface regions further have respective curvilinear contact surfaces adapted to provide a plurality of bearing contact points on the bearing support members.

  3. Axial Halbach Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.

    2008-01-01

    Axial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly reliable noncontact bearings for future high-speed rotary machines that may be used in such applications as aircraft, industrial, and land-vehicle power systems and in some medical and scientific instrumentation systems. Axial Halbach magnetic bearings are passive in the sense that unlike most other magnetic bearings that have been developed in recent years, they effect stable magnetic levitation without need for complex active control.

  4. Design, synthesis and biological evaluation of di-substituted cinnamic hydroxamic acids bearing urea/thiourea unit as potent histone deacetylase inhibitors.

    PubMed

    Ning, Chengqing; Bi, Yanjing; He, Yujun; Huang, WenYuan; Liu, Lifei; Li, Yi; Zhang, Sihan; Liu, Xiaoyu; Yu, Niefang

    2013-12-01

    A novel class of di-substituted cinnamic hydroxamic acid derivatives containing urea or thiourea unit was designed, synthesized and evaluated as HDAC inhibitors. All tested compounds demonstrated significant HDAC inhibitory activities and anti-proliferative effects against diverse human tumor cell lines. Among them, 7l exhibited most potent pan-HDAC inhibitory activity, with an IC50 value of 130 nM. It also showed strong cellular inhibition against diverse cell lines including HCT-116, MCF-7, MDB-MB-435 and NCI-460, with GI50 values of 0.35, 0.22, 0.51 and 0.48 μM, respectively.

  5. 1-Way Bearing

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2003-01-01

    A one-way bearing is provided having sprags and rolling bearings both disposed between an inner and an outer race. The sprags may comprise three-dimensional sprags for preventing rotation in a non-preferential direction. The roll- ing bearings may comprise thrust rollers for transmitting axial, tilt, and radial loads between the inner and outer races.

  6. Supertough Stainless Bearing Steel

    NASA Technical Reports Server (NTRS)

    Olson, Gregory B.

    1995-01-01

    Composition and processing of supertough stainless bearing steel designed with help of computer-aided thermodynamic modeling. Fracture toughness and hardness of steel exceeds those of other bearing steels like 440C stainless bearing steel. Developed for service in fuel and oxidizer turbopumps on Space Shuttle main engine. Because of strength and toughness, also proves useful in other applications like gears and surgical knives.

  7. Lung Transplantation

    MedlinePlus

    ... who have severe COPD Cystic fibrosis Idiopathic pulmonary fibrosis Alpha-1 antitrypsin deficiency Pulmonary hypertension Complications of lung transplantation include rejection of the transplanted lung and infection. NIH: National Heart, Lung, and Blood Institute

  8. Lung disease

    MedlinePlus

    ... the lungs to take in oxygen and release carbon dioxide. People with this type of lung disorder often ... the lungs to take up oxygen and release carbon dioxide. These diseases may also affect heart function. An ...

  9. Collapsed Lung

    MedlinePlus

    A collapsed lung happens when air enters the pleural space, the area between the lung and the chest wall. If it is a ... is called pneumothorax. If only part of the lung is affected, it is called atelectasis. Causes of ...

  10. Cryogenic Hybrid Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Meeks, Crawford R.; Dirusso, Eliseo; Brown, Gerald V.

    1994-01-01

    Cryogenic hybrid magnetic bearing is example of class of magnetic bearings in which permanent magnets and electromagnets used to suspend shafts. Electromagnets provide active control of position of shaft. Bearing operates at temperatures from -320 degrees F (-196 degrees C) to 650 degrees F (343 degrees C); designed for possible use in rocket-engine turbopumps, where effects of cryogenic environment and fluid severely limit lubrication of conventional ball bearings. This and similar bearings also suitable for terrestrial rotating machinery; for example, gas-turbine engines, high-vacuum pumps, canned pumps, precise gimbals that suspend sensors, and pumps that handle corrosive or gritty fluids.

  11. Cryogenic Hybrid Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Meeks, Crawford R.; Dirusso, Eliseo; Brown, Gerald V.

    1994-01-01

    Cryogenic hybrid magnetic bearing is example of class of magnetic bearings in which permanent magnets and electromagnets used to suspend shafts. Electromagnets provide active control of position of shaft. Bearing operates at temperatures from -320 degrees F (-196 degrees C) to 650 degrees F (343 degrees C); designed for possible use in rocket-engine turbopumps, where effects of cryogenic environment and fluid severely limit lubrication of conventional ball bearings. This and similar bearings also suitable for terrestrial rotating machinery; for example, gas-turbine engines, high-vacuum pumps, canned pumps, precise gimbals that suspend sensors, and pumps that handle corrosive or gritty fluids.

  12. TOPICAL REVIEW: Superconducting bearings

    NASA Astrophysics Data System (ADS)

    Hull, John R.

    2000-02-01

    The physics and technology of superconducting bearings is reviewed. Particular attention is given to the use of high-temperature superconductors (HTSs) in rotating bearings. The basic phenomenology of levitational forces is presented, followed by a brief discussion of the theoretical models that can be used for conceptual understanding and calculations. The merits of various HTS bearing designs are presented, and the behaviour of HTS bearings in typical situations is discussed. The article concludes with a brief survey of various proposed applications for HTS bearings.

  13. Bearings: Technology and needs

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.

    1982-01-01

    A brief status report on bearing technology and present and near-term future problems that warrant research support is presented. For rolling element bearings a material with improved fracture toughness, life data in the low Lambda region, a comprehensive failure theory verified by life data and incorporated into dynamic analyses, and an improved corrosion resistant alloy are perceived as important needs. For hydrodynamic bearings better definition of cavitation boundaries and pressure distributions for squeeze film dampers, and geometry optimization for minimum power loss in turbulent film bearings are needed. For gas film bearings, foil bearing geometries that form more nearly optimum film shapes for maximum load capacity, and more effective surface protective coatings for high temperature operation are needed.

  14. Bear Spray Safety Program

    USGS Publications Warehouse

    Blome, C.D.; Kuzniar, R.L.

    2009-01-01

    A bear spray safety program for the U.S. Geological Survey (USGS) was officially initiated by the Firearms Safety Committee to address accident prevention and to promote personnel training in bear spray and its transportation, storage, and use for defense against wild animals. Used as part of a system including firearms, or used alone for those who choose not to carry a firearm, bear spray is recognized as an effective tool that can prevent injury in a wild animal attack.

  15. Bearing restoration by grinding

    NASA Technical Reports Server (NTRS)

    Hanau, H.; Parker, R. J.; Zaretsky, E. V.; Chen, S. M.; Bull, H. L.

    1976-01-01

    A joint program was undertaken by the NASA Lewis Research Center and the Army Aviation Systems Command to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. No bearing failures occurred related to the restoration by grinding process. The risk and cost of a bearing restoration by grinding programs was analyzed. A microeconomic impact analysis was performed.

  16. Linear magnetic bearing

    NASA Technical Reports Server (NTRS)

    Studer, P. A. (Inventor)

    1983-01-01

    A linear magnetic bearing system having electromagnetic vernier flux paths in shunt relation with permanent magnets, so that the vernier flux does not traverse the permanent magnet, is described. Novelty is believed to reside in providing a linear magnetic bearing having electromagnetic flux paths that bypass high reluctance permanent magnets. Particular novelty is believed to reside in providing a linear magnetic bearing with a pair of axially spaced elements having electromagnets for establishing vernier x and y axis control. The magnetic bearing system has possible use in connection with a long life reciprocating cryogenic refrigerator that may be used on the space shuttle.

  17. Extending bearing life

    SciTech Connect

    Boyer, D.

    1997-08-01

    Long-term bearing operation cannot be achieved unless proper handling, storage, installation, and maintenance procedures are followed. These factors can shorten--sometimes drastically--expected bearing service life. Failures are generally related to improper lubrication or installation and induced conditions. Most major bearing manufacturers offer technical assistance in inspection, evaluation, and reporting on bearings which have failed in service. Actual percentages associated with each failure category vary, depending on the source, but generally they are 70% from lubrication and installation, 20% from induced factors, and 10% from reaching their fatigue limit or design life. The paper describes lubricant-related failures and procedures for the correct handling, storage, installation, and maintenance.

  18. Damper bearing rotordynamics

    NASA Technical Reports Server (NTRS)

    Elrod, David A.

    1990-01-01

    High side loads reduce the life of the Space Shuttle Main Engine (SSME) High Pressure Oxygen Turbopump (HPOTP) bearings. High stiffness damper seals were recommended to reduce the loads on the pump and turbine end bearings in the HPOTP. The seals designed for use on the pump end are expected to adequately reduce the bearing loads; the predicted performance of the planned turbine end seal is marginal. An alternative to the suggested turbine end seal design is a damper bearing with radial holes from the pressurized center of the turbopump rotor, feeding a smooth land region between two rough-stator/smooth-rotor annular seals. An analysis was prepared to predict the leakage and rotor dynamic coefficients (stiffness, damping, and added mass) of the damper bearing. Governing equations of the seal analysis modified to model the damper bearing; differences between the upstream conditions of the damper bearing and a typical annular seal; prediction of the damper bearing analysis; and assumptions of the analysis which require further investigation are described.

  19. Cylindrical bearing analysis

    NASA Technical Reports Server (NTRS)

    Kleckner, R. J.; Pirvics, J.

    1981-01-01

    Program CYBEAN computes behavior of rolling-element bearings including effects of bearing geometry, shaft misalinement, and temperature. Accurate assessment is possible for various outer-ring and housing configurations. CYBEAN is structured for coordinated execution of modules that perform specific analytical tasks. It is written in FORTRAN IV for use on the UNIVAC 1100/40 computer.

  20. Bearing fatigue investigation 3

    NASA Technical Reports Server (NTRS)

    Nahm, A. H.; Bamberger, E. N.; Signer, H. R.

    1982-01-01

    The operating characteristics of large diameter rolling-element bearings in the ultra high speed regimes expected in advanced turbine engines for high performance aircraft were investigated. A high temperature lubricant, DuPont Krytox 143 AC, was evaluated at bearing speeds to 3 million DN. Compared to the results of earlier, similar tests using a MIL-L-23699 (Type II) lubricant, bearings lubricated with the high density Krytox fluid showed significantly higher power requirements. Additionally, short bearing lives were observed when this fluid was used with AISI M50 bearings in an air atmosphere. The primary mode of failure was corrosion initiated surface distress (fatigue) on the raceways. The potential of a case-carburized bearing to sustain a combination of high-tangential and hertzian stresses without experiencing race fracture was also investigated. Limited full scale bearing tests of a 120 mm bore ball bearing at a speed of 25,000 rpm (3 million DN) indicated that a carburized material could sustain spalling fatigue without subsequent propagation to fracture. Planned life tests of the carburized material had to be aborted, however, because of apparent processing-induced material defects.

  1. Low cost lobed bearing

    NASA Technical Reports Server (NTRS)

    Schuller, F. T.

    1970-01-01

    Separate sectors for each lobed area of the bearing are assembled into the bearing housing individually and bolted tightly against the housing inside diameter. The center of a grinding wheel and the center of the housing are offset, resulting in the desired inner radius and tilt of the sector.

  2. Passive Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Studer, P. A.

    1983-01-01

    Magnetic bearing for limited rotation devices requires no feedback control system to sense and correct shaft position. Passive Magnetic Torsion Bearing requires no power supply and has no rubbing parts. Torsion wire restrains against axial instability. Magnetic flux geometry chosen to assure lateral stability with radial restoring force that maintains alignment.

  3. OTV bearing deflection investigation

    NASA Technical Reports Server (NTRS)

    Reimer, B. L.; Diepenbrock, R. T.; Millis, M. G.

    1993-01-01

    The primary goal of the Bearing Deflectometer Investigation was to gain experience in the use of fiber optic displacement probe technology for bearing health monitoring in a liquid hydrogen turbo pump. The work specified in this Task Order was conducted in conjunction with Air Force Rocket Propulsion Laboratory Contract F04611-86-C-0010. APD conducted the analysis and design coordination to provide a displacement probe design compatible with the XLR-134 liquid hydrogen turbo pump assembly (TPA). Specifications and requirements of the bearing deflectometer were established working with Mechanical Technology Instruments, Inc. (MTI). The TPA design accommodated positioning of the probe to measure outer race cyclic deflections of the pump inlet bearing. The fiber optic sensor was installed as required in the TPA and sensor output was recorded during the TPA testing. Data review indicated that no bearing deflection signature could be differentiated from the inherent system noise. Alternate sensor installations were not investigated, but might yield different results.

  4. Arcturus and the Bears

    NASA Astrophysics Data System (ADS)

    Antonello, E.

    2009-08-01

    Arcturus is the brightest star in Bootes. The ancient Greek name Arktouros means Bear Guard. The star, however, is not close to Ursa Maior (Big She-Bear) and Ursa Minor (Little She-Bear), as the name would suggest. This curious discrepancy could be explained by the star proper motion, assuming the name Bear Guard is a remote cultural heritage. The proper motion analysis could allow us to get an insight also into an ancient myth regarding Ursa Maior. Though we cannot explain scientifically such a myth, some interesting suggestions can be obtained about its possible origin, in the context of the present knowledge of the importance of the cult of the bear both during the Palaeolithic times and for several primitive populations of modern times, as shown by the ethnological studies.

  5. Touchdown Ball-Bearing System for Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Kingsbury, Edward P.; Price, Robert; Gelotte, Erik; Singer, Herbert B.

    2003-01-01

    The torque-limited touchdown bearing system (TLTBS) is a backup mechanical-bearing system for a high-speed rotary machine in which the rotor shaft is supported by magnetic bearings in steady-state normal operation. The TLTBS provides ball-bearing support to augment or supplant the magnetic bearings during startup, shutdown, or failure of the magnetic bearings. The TLTBS also provides support in the presence of conditions (in particular, rotational acceleration) that make it difficult or impossible to control the magnetic bearings or in which the magnetic bearings are not strong enough (e.g., when the side load against the rotor exceeds the available lateral magnetic force).

  6. Lung transplant

    MedlinePlus

    ... diseases that may require a lung transplant are: Cystic fibrosis Damage to the arteries of the lung because ... BC; Clinical Practice Guidelines for Pulmonary Therapies Committee; ... Therapies Committee. Cystic fibrosis pulmonary guidelines: ...

  7. Good bearings reduce downtime

    SciTech Connect

    Kinney, J.; Foster, J.

    1982-12-01

    Points out that a poorly maintained $100 bearing can hold up the operation of a $1-million conveyor. Of all the moving parts in a coal conveyor system, few cost less or last longer than anti-friction bearings. Most modern conveyor systems are equipped with 2 types of bearings: troughing idlers, spaced at regular intervals to support the conveyor belt as it travels throughout the system, and the adaptermounted spherical roller bearing pillow blocks that are used in the head, tail, bend and takeup pulleys that drive, alter the direction of, or regulate tension in the belt to allow for repairs or splicing. Explains how pillow blocks should handle radial or axial loads, how to mount bearings correctly, and how rings prevent infiltration. Concludes that by making certain that the proper bearing types are built into the system initially, or used as replacements in case of failures, paying close attention to installation procedures and devoting adequate time to maintenance, conveyor system bearings can provide decades of problem-free service.

  8. HTS magnetic bearings

    NASA Astrophysics Data System (ADS)

    Werfel, Frank N.; Flögel-Delor, Uta; Rothfeld, Rolf; Wippich, Dieter; Riedel, Thomas

    2002-08-01

    Radial HTS magnetic bearings (SMB) up to 200 mm size are developed and tested in prototype fast rotating machines to demonstrate the potential to replace conventional bearings. The individual rotational bearing components HTS and PM, their physical interaction and technology is reviewed. Characterisation experiments are conducted to understand the rotor dynamic behaviour. In terms of unbalance and critical speeds the suspended wheels and rotors compare favourably with conventional bearing devices. The rationale of our present bearing technology lies in the assembling of both low-speed magnetic bearings for centrifugal and wafer processing units up to 20,000 rpm as well as a high-speed optical mirror accelerated to rim speed of more than 500 m/s (174,000 rpm) confirming stable low-drag and low energy operation. Two new-type U shaped semicircle HTS bearings coupled each with a 6 W/80 K cryocooler of the Stirling type allow the contact-free operation of a Si wafer carrier in semiconductor wet processes.

  9. Magnetically-controlled bearing lubrication

    NASA Technical Reports Server (NTRS)

    Whitaker, A. F.

    1977-01-01

    Proposed magnetic-lubricant ball-bearing assembly has permanently-magnetized bearing retainer fabricated of porous material. Pores of retainer are filled with ferrolubricant. Surface tension causes retainer to deliver sufficient lubricant to nonmagnetic ball bearings.

  10. Ball Bearing Mechanics

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1981-01-01

    Load-deflection relationships for different types of elliptical contacts such as those found in a ball bearing are developed. Simplified expressions that allow quick calculations of deformation to be made simply from a knowledge of the applied load, the material properties, and the geometry of the contacting elements are presented. Ball bearings subjected to radial, thrust and combined ball loads are analyzed. A design criterion for fatigue life of ball bearings is developed. The section of a satisfactory lubricant, as well as describing systems that provide a constant flow of lubricant to the contact, is considered.

  11. Ball and Roller Bearings. A Teaching Reference.

    ERIC Educational Resources Information Center

    American Association for Vocational Instructional Materials, Athens, GA.

    The manual provides a subject reference for ball and roller bearings. The following topics are included: (1) bearing nomenclature, (2) bearing uses, (3) bearing capacities, (4) shop area working conditions, (5) bearing removal, (6) bearing cleaning and inspection, (7) bearing replacement, (8) bearing lubrication, (9) bearing installation, (10)…

  12. Arkansas black bear hunter survey

    USGS Publications Warehouse

    Pharris, Larry D.; Clark, Joseph D.

    1987-01-01

    Questionnaires were mailed to black bear (Ursus americanus) hunters in Arkansas following the 1980-84 bear seasons to determine participation, hunter success, and number of bears observed by hunters. Man-days of hunting to harvest a bear ranged from 148 to 671 and hunter success ranged from 0.4% to 2.2%. With the exception of 1980, number of permits issued, man-days of bear hunting, and bears harvested appear affected by hunting permit cost. 

  13. Roller bearing geometry design

    NASA Technical Reports Server (NTRS)

    Savage, M.; Pinkston, B. H. W.

    1976-01-01

    A theory of kinematic stabilization of rolling cylinders is extended and applied to the design of cylindrical roller bearings. The kinematic stabilization mechanism puts a reverse skew into the rolling elements by changing the roller taper. Twelve basic bearing modification designs are identified amd modeled. Four have single transverse convex curvature in their rollers while eight have rollers which have compound transverse curvature made up of a central cylindrical band surrounded by symmetric bands with slope and transverse curvature. The bearing designs are modeled for restoring torque per unit axial displacement, contact stress capacity, and contact area including dynamic loading, misalignment sensitivity and roller proportion. Design programs are available which size the single transverse curvature roller designs for a series of roller slopes and load separations and which design the compound roller bearings for a series of slopes and transverse radii of curvature. The compound rollers are proportioned to have equal contact stresses and minimum size. Design examples are also given.

  14. Gear bearing drive

    NASA Technical Reports Server (NTRS)

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  15. Surface Analysis of Bearings,

    DTIC Science & Technology

    1993-03-31

    standards, applied laser spectroscopy, laser chemistry, laser optoelectronics, phase conjugation and coherent imaging, solar cell physics, battery...of a thrust bearing raceway lubricated with sputter-deposited MoS2 (1 pim thick) after testing and failure, defined as a significant torque rise...200 gim 100 jgm Figure 3. SEM micrographs of a 440C steel thrust bearing raceway lubricated with sputter-deposited MoS2 (1 pum thick) after testing

  16. High speed hybrid bearing comprising a fluid bearing and a rolling bearing convected in series

    NASA Technical Reports Server (NTRS)

    Anderson, W. J. (Inventor)

    1973-01-01

    A description is given of an antifriction bearing and a process by which its fatigue life may be extended. The method involves a rotating shaft supported by a fluid bearing and a rolling element bearing coupled in series. Each bearing turns at a fraction of the rotational speed of the shaft. The fluid bearing is preferably conical, thereby providing thrust and radial load support in a single bearing structure.

  17. Load responsive hydrodynamic bearing

    DOEpatents

    Kalsi, Manmohan S.; Somogyi, Dezso; Dietle, Lannie L.

    2002-01-01

    A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

  18. Magnetic bearing and motor

    NASA Technical Reports Server (NTRS)

    Studer, P. A. (Inventor)

    1983-01-01

    A magnetic bearing for passively suspending a rotatable element subjected to axial and radial thrust forces is disclosed. The magnetic bearing employs a taut wire stretched along the longitudinal axis of the bearing between opposed end pieces and an intermediate magnetic section. The intermediate section is segmented to provide oppositely directed magnetic flux paths between the end pieces and may include either an axially polarized magnets interposed between the segments. The end pieces, separated from the intermediate section by air gaps, control distribution of magnetic flux between the intermediate section segments. Coaxial alignment of the end pieces with the intermediate section minimizes magnetic reluctance in the flux paths endowing the bearing with self-centering characteristics when subjected to radial loads. In an alternative embodiment, pairs of oppositely wound armature coils are concentrically interposed between segments of the intermediate section in concentric arcs adjacent to radially polarized magnets to equip a magnetic bearing as a torsion drive motor. The magnetic suspension bearing disclosed provides long term reliability without maintenance with application to long term space missions such as the VISSR/VAS scanning mirror instrument in the GOES program.

  19. Lung Organogenesis

    PubMed Central

    Warburton, David; El-Hashash, Ahmed; Carraro, Gianni; Tiozzo, Caterina; Sala, Frederic; Rogers, Orquidea; De Langhe, Stijn; Kemp, Paul J.; Riccardi, Daniela; Torday, John; Bellusci, Saverio; Shi, Wei; Lubkin, Sharon R; Jesudason, Edwin

    2011-01-01

    Developmental lung biology is a field that has the potential for significant human impact: lung disease at the extremes of age continues to cause major morbidity and mortality worldwide. Understanding how the lung develops holds the promise that investigators can use this knowledge to aid lung repair and regeneration. In the decade since the “molecular embryology” of the lung was first comprehensively reviewed, new challenges have emerged—and it is on these that we focus the current review. Firstly, there is a critical need to understand the progenitor cell biology of the lung in order to exploit the potential of stem cells for the treatment of lung disease. Secondly, the current familiar descriptions of lung morphogenesis governed by growth and transcription factors need to be elaborated upon with the reinclusion and reconsideration of other factors, such as mechanics, in lung growth. Thirdly, efforts to parse the finer detail of lung bud signaling may need to be combined with broader consideration of overarching mechanisms that may be therapeutically easier to target: in this arena, we advance the proposal that looking at the lung in general (and branching in particular) in terms of clocks may yield unexpected benefits. PMID:20691848

  20. Investigation of Pressurized Wave Bearings

    NASA Technical Reports Server (NTRS)

    Keith, Theo G., Jr.; Dimofte, Florin

    2003-01-01

    The wave bearing has been pioneered and developed by Dr. Dimofte over the past several years. This bearing will be the main focus of this research. It is believed that the wave bearing offers a number of advantages over the foil bearing, which is the bearing that NASA is currently pursuing for turbomachinery applications. The wave bearing is basically a journal bearing whose film thickness varies around the circumference approximately sinusoidally, with usually 3 or 4 waves. Being a rigid geometry bearing, it provides precise control of shaft centerlines. The wave profile also provides good load capacity and makes the bearing very stable. Manufacturing techniques have been devised that should allow the production of wave bearings almost as cheaply as conventional full-circular bearings.

  1. Climate Drives Polar Bear Origins

    USDA-ARS?s Scientific Manuscript database

    In their provocative analysis of northern bears (“Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage,” Reports, 20 April, p. 344), F. Hailer et al. use independent nuclear loci to show that polar bears originated during the middle Pleistocene, rather than during t...

  2. Watchable Wildlife: The Black Bear

    Treesearch

    Lynn L. Rogers

    1992-01-01

    Black bears are the bears people most often encounter. Black bears live in forests over much of North America, unlike grizzlies that live only in Alaska, northern and western Canada, and the northern Rocky Mountains. This brochure presents the latest information on black bear life and how this species responds to an ever-increasing number of campers, hikers, and...

  3. Fault tolerant magnetic bearings

    SciTech Connect

    Maslen, E.H.; Sortore, C.K.; Gillies, G.T.; Williams, R.D.; Fedigan, S.J.; Aimone, R.J.

    1999-07-01

    A fault tolerant magnetic bearing system was developed and demonstrated on a large flexible-rotor test rig. The bearing system comprises a high speed, fault tolerant digital controller, three high capacity radial magnetic bearings, one thrust bearing, conventional variable reluctance position sensors, and an array of commercial switching amplifiers. Controller fault tolerance is achieved through a very high speed voting mechanism which implements triple modular redundancy with a powered spare CPU, thereby permitting failure of up to three CPU modules without system failure. Amplifier/cabling/coil fault tolerance is achieved by using a separate power amplifier for each bearing coil and permitting amplifier reconfiguration by the controller upon detection of faults. This allows hot replacement of failed amplifiers without any system degradation and without providing any excess amplifier kVA capacity over the nominal system requirement. Implemented on a large (2440 mm in length) flexible rotor, the system shows excellent rejection of faults including the failure of three CPUs as well as failure of two adjacent amplifiers (or cabling) controlling an entire stator quadrant.

  4. Fluid lubricated bearing assembly

    DOEpatents

    Boorse, Henry A.; Boeker, Gilbert F.; Menke, John R.

    1976-01-01

    1. A support for a loaded rotatable shaft comprising in combination on a housing having a fluid-tight cavity encasing an end portion of said shaft, a thrust bearing near the open end of said cavity for supporting the axial thrust of said shaft, said thrust bearing comprising a thrust plate mounted in said housing and a thrust collar mounted on said shaft, said thrust plate having a central opening the peripheral portion of which is hermetically sealed to said housing at the open end of said cavity, and means for supplying a fluid lubricant to said thrust bearing, said thrust bearing having a lubricant-conducting path connecting said lubricant supplying means with the space between said thrust plate and collar intermediate the peripheries thereof, the surfaces of said plate and collar being constructed and arranged to inhibit radial flow of lubricant and, on rotation of said thrust collar, to draw lubricant through said path between the bearing surfaces and to increase the pressure therebetween and in said cavity and thereby exert a supporting force on said end portion of said shaft.

  5. Tribology of alternative bearings.

    PubMed

    Fisher, John; Jin, Zhongmin; Tipper, Joanne; Stone, Martin; Ingham, Eileen

    2006-12-01

    The tribological performance and biological activity of the wear debris produced has been compared for highly cross-linked polyethylene, ceramic-on-ceramic, metal-on-metal, and modified metal bearings in a series of in vitro studies from a single laboratory. The functional lifetime demand of young and active patients is 10-fold greater than the estimated functional lifetime of traditional polyethylene. There is considerable interest in using larger diameter heads in these high demand patients. Highly cross-linked polyethylene show a four-fold reduction in functional biological activity. Ceramic-on-ceramic bearings have the lowest wear rates and least reactive wear debris. The functional biological activity is 20-fold lower than with highly cross-linked polyethylene. Hence, ceramic-on-ceramic bearings address the tribological lifetime demand of highly active patients. Metal-on-metal bearings have substantially lower wear rates than highly cross-linked polyethylene and wear decreases with head diameter. Bedding in wear is also lower with reduced radial clearance. Differential hardness ceramic-on-metal bearings and the application of ceramic-like coatings reduce metal wear and ion levels.

  6. Radial Clearance of Antifriction Bearings,

    DTIC Science & Technology

    The article concerns in detail the radial clearance of different antifriction bearings which belong to important parameters which influence the...longevity of the bearing to a certain extent. The effect of the influence of assembly and the wear on the radial clearance of different bearings, the...antifriction bearings operate and their respect in clearance and assembly can contribute substantially to decreasing the daily disproportionate bearing consumption for the repair and maintenance of different machines. (Author)

  7. Radial Halbach Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.

    2009-01-01

    Radial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly reliable noncontact bearings for future high-speed rotary machines that may be used in such applications as aircraft, industrial, and land-vehicle power systems and in some medical and scientific instrumentation systems. Radial Halbach magnetic bearings are based on the same principle as that of axial Halbach magnetic bearings, differing in geometry as the names of these two types of bearings suggest. Both radial and axial Halbach magnetic bearings are passive in the sense that unlike most other magnetic bearings that have been developed in recent years, they effect stable magnetic levitation without need for complex active control. Axial Halbach magnetic bearings were described in Axial Halbach Magnetic Bearings (LEW-18066-1), NASA Tech Briefs, Vol. 32, No. 7 (July 2008), page 85. In the remainder of this article, the description of the principle of operation from the cited prior article is recapitulated and updated to incorporate the present radial geometry. In simplest terms, the basic principle of levitation in an axial or radial Halbach magnetic bearing is that of the repulsive electromagnetic force between (1) a moving permanent magnet and (2) an electric current induced in a stationary electrical conductor by the motion of the magnetic field. An axial or radial Halbach bearing includes multiple permanent magnets arranged in a Halbach array ("Halbach array" is defined below) in a rotor and multiple conductors in the form of wire coils in a stator, all arranged so the rotary motion produces an axial or radial repulsion that is sufficient to levitate the rotor. A basic Halbach array (see Figure 1) consists of a row of permanent magnets, each oriented so that its magnetic field is at a right angle to that of the adjacent magnet, and the right-angle turns are sequenced so as to maximize the magnitude of the magnetic flux density on one side of the row while

  8. Turbogear bearing analysis

    SciTech Connect

    Cassolato, B.M.

    1997-04-01

    To optimize process energy efficiency, many plants are considering variable-speed electric motor drives with speed-increasing gears for centrifugal compressors. Variable-speed systems are much more complex than fixed-speed systems, especially when power and speed change independently across the compressor performance map, for example, from start-of-run to end-of-run. There are more mechanical design issues that impact reliable operation. Bearing analysis of turbogears subjected to these conditions is an important consideration. Many turbomachines have a simple bearing load characteristic comprised principally of the rotating assembly weight. Helical gear loads are more complex because of the influence of tooth geometry and torque magnitude. A force analysis is required to define parameters for a meaningful rotordynamic study, and evaluate tooth integrity and bearing performance.

  9. Partial tooth gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  10. Solving bearing overheating problems

    SciTech Connect

    Jendzurski, T.

    1995-05-08

    Overheating is a major indicator, along with vibration and noise, of an underlying problem affecting a bearing or related components. Because normal operating temperatures vary widely from one application to another, no single temperature is a reliable sign of overheating in every situation. By observing an application when it is running smoothly, a technician can establish a benchmark temperature for a particular bearing arrangement. Wide deviations from this accepted norm generally indicate troublesome overheating. The list of possible causes of over-heating ranges from out-of-round housings and oversize shaft diameters to excessive lubrication and bearing preloading. These causes fall into two major categories: improper or faulty lubrication and mechanical problems, such as incorrect fits and tolerances. These are discussed along with solutions.

  11. [The lung].

    PubMed

    Martinod, Emmanuel; Uzunhan, Yurdagül; Radu, Dana M; Seguin, Agathe; Boddaert, Guillaume; Valeyre, Dominique; Planès, Carole; Carpentier, Alain

    2011-10-01

    Lung transplantation is still the only curative treatment for end-stage pulmonary diseases. The results remain poor, however, because of the limited availability of lung donors, chronic rejection, and complications related to immunosuppressive therapy. The use of a bioartificial lung generated from autologous cells could offer a solution. We have demonstrated that in vivo epithelial and cartilage regeneration of the airways is feasible with the use of an aortic tissue matrix. Other studies show that in vitro and in vivo airway regeneration, respectively, can be obtained by using bio-engineering and heterotopic allograft implantation. A more complex challenge is the creation of an artificial lung Indeed, this would require the use of an elastic matrix that can promote regeneration of the different lung components (airways, alveoli, vessels) over a large surface area, thus allowing ventilation, blood perfusion and gas exchanges. Recent studies have demonstrated the possibility of in vitro and in vivo regeneration of lung tissue from autologous cells, and especially stem cells. This emerging research field is currently dominated by the use of decellularized lung matrices and autologous epithelial and endothelial cells. Implantation of such a recellularized matrix in animals has proved the feasibility of a functional bio-artificial lung. The first human transplantation of a bio-artificial lung should be possible within 10-20 years.

  12. Targeted radiotherapy with [(90)Y]-SMT 487 in mice bearing human nonsmall cell lung tumor xenografts induced to express human somatostatin receptor subtype 2 with an adenoviral vector.

    PubMed

    Rogers, Buck E; Zinn, Kurt R; Lin, Chin-Yu; Chaudhuri, Tandra R; Buchsbaum, Donald J

    2002-02-15

    Novel approaches to increasing the therapeutic efficacy of targeted radiotherapy of cancer are required. One strategy to achieve this goal is to induce high-level expression of a receptor on the surface of tumor cells that can be targeted with a radiolabeled peptide. The objectives of this study were to 1) induce somatostatin receptor (SSTr2) expression in tumor cells using an adenovirus encoding the SSTr2 gene (AdSSTr2), 2) demonstrate tumor localization of [(111)In]-DTPA-D-Phe(1)-octreotide in AdSSTr2-injected tumors, and 3) show therapeutic efficacy with [(90)Y]-DOTA-D-Phe(1)-Tyr(3)-octreotide ([(90)Y]-SMT 487). SSTr2 expression was validated in vitro by the binding and subsequent internalization of [(111)In]-DTPA-D-Phe(1)-octreotide (21.3% per mg of total protein) in A-427 cells infected with AdSSTr2. In vivo imaging confirmed 5- to 10-fold greater uptake 5.5 hours after intravenous administration of [(111)In]-DTPA-D-Phe(1)-octreotide in AdSSTr2-injected tumors relative to control tumors. For therapy studies, mice bearing established subcutaneous A-427 tumors were given two intratumoral injections of AdSSTr2 1 week apart, followed by an intravenous injection of 400 microCi or 500 microCi [(90)Y]-SMT 487 at 2 and 4 days after each adenoviral administration. Control animals either were not treated or were administered 500 microCi [(90)Y]-SMT 487 with no AdSSTr2 injection. These studies showed that untreated animals and animals treated with no virus and 500 microCi [(90)Y]-SMT 487 had median tumor quadrupling times of 16 and 25 days, respectively. Mice administered AdSSTr2 and either 400 microCi or 500 microCi of [(90)Y]-SMT 487 demonstrated significantly longer median tumor quadrupling times of 40 and 44 days, respectively (P < 0.02). These studies are the first to demonstrate in vivo therapeutic efficacy using a radiolabeled peptide targeted to a receptor expressed on the surface of tumor cells following gene transfer. Future studies will focus on the

  13. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    1999-01-01

    Methods and apparatus are provided for a blood pump bearing system within a pump housing to support long-term high-speed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the shaft to support high speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  14. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    2000-01-01

    An apparatus is provided for a blood pump bearing system within a pump housing to support long-term highspeed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the Ir shaft to support big speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  15. Modular gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2009-01-01

    A gearing system using modular gear bearing components. Each component is composed of a core, one or more modules attached to the core and two or more fastening modules rigidly attaching the modules to the core. The modules, which are attached to the core, may consist of gears, rollers or gear bearing components. The core orientation affects the orientation of the modules attached to the core. This is achieved via the keying arrangement of the core and the component modules that attach to the core. Such an arrangement will also facilitate the phase tuning of gear modules with respect to the core and other gear modules attached to the core.

  16. Hybrid superconductor magnet bearings

    SciTech Connect

    Chu, W.

    1995-04-01

    Hybrid superconductor magnet bearings (HSMB`s) utilize high temperature superconductors (HTS`s) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS`s, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, the authors present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  17. Composite Bear Canister

    NASA Technical Reports Server (NTRS)

    Chung, W. Richard; Jara, Steve; Suffel, Susan

    2003-01-01

    To many national park campers and mountain climbers saving their foods in a safe and unbreakable storage container without worrying being attacked by a bear is a challenging task. In some parks, the park rangers have mandated that park visitors rent a bear canister for their food storage. Commercially available bear canisters are made of ABS plastic, weigh 2.8 pounds, and have a 180 cubic inch capacity for food storage. A new design with similar capacity was conducted in this study to reduce its weight and make it a stiffer and stronger canister. Two prototypes incorporating carbon prepreg with and without honeycomb constructions were manufactured using hand lay-up and vacuum bag forming techniques. A 6061-T6-aluminum ring was machined to dimensions in order to reinforce the opening area of the canister. Physical properties (weight and volume) along with mechanical properties (flexural strength and specific allowable moment) of the newly fabricated canisters are compared against the commercial ones. The composite canister weighs only 56% of the ABS one can withstand 9 times of the force greater. The advantages and limitations of using composite bear canisters will be discussed in the presentation.

  18. History of ball bearings

    NASA Technical Reports Server (NTRS)

    Dowson, D.; Hamrock, B. J.

    1981-01-01

    The familiar precision rolling-element bearings of the twentieth century are products of exacting technology and sophisticated science. Their very effectiveness and basic simplicity of form may discourage further interest in their history and development. Yet the full story covers a large portion of recorded history and surprising evidence of an early recognition of the advantages of rolling motion over sliding action and progress toward the development of rolling-element bearings. The development of rolling-element bearings is followed from the earliest civilizations to the end of the eighteenth century. The influence of general technological developments, particularly those concerned with the movement of large building blocks, road transportation, instruments, water-raising equipment, and windmills are discussed, together with the emergence of studies of the nature of rolling friction and the impact of economic factors. By 1800 the essential features of ball and rolling-element bearings had emerged and it only remained for precision manufacture and mass production to confirm the value of these fascinating machine elements.

  19. The Teddy Bears' Disc.

    ERIC Educational Resources Information Center

    Laurillard, Diana

    1985-01-01

    Reports an evaluation of the Teddy Bear disc, an interactive videodisc developed at the Open University for a second-level course in metallurgy and materials technology. Findings from observation of students utilizing the videodisc are reviewed; successful design features and design problems are considered; and development costs are outlined. (MBR)

  20. Hybrid superconductor magnet bearings

    NASA Astrophysics Data System (ADS)

    Chu, Wei-Kan

    1995-04-01

    Hybrid superconductor magnet bearings (HSMB's) utilize high temperature superconductors (HTS's) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS's, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, we present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  1. Magnetically leviated superconducting bearing

    DOEpatents

    Weinberger, Bernard R.; Lynds, Jr., Lahmer

    1993-01-01

    A magnetically levitated superconducting bearing includes a magnet (2) mounted on a shaft (12) that is rotatable around an axis of rotation and a Type II superconductor (6) supported on a stator (14) in proximity to the magnet (2). The superconductor (6) is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet (2) to produce an attractive force that levitates the magnet (2) and supports a load on the shaft (12). The interaction between the superconductor (6) and magnet(2) also produces surface screening currents (8) that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature (16, 18). The bearing could also be constructed so the magnet (2) is supported on the stator (14) and the superconductor (6) is mounted on the shaft (12). The bearing can be operated by cooling the superconductor (6) to its superconducting state in the presence of a magnetic field.

  2. Bearings Incorporating Deadband Rollers

    NASA Technical Reports Server (NTRS)

    Gualtieri, Guy V.

    1996-01-01

    Bearings in high-pressure turbopump redesigned to incorporate rollers allowing limited axial motion within small deadband. Does not permit radial deadband motion. Axial deadband motion used for rotor-thrust-balance control. Design eliminates some nonlinearities in dynamics of pump rotor and assists in suppressing vibrations at harmonics of frequency of rotation.

  3. Hybrid superconductor magnet bearings

    NASA Technical Reports Server (NTRS)

    Chu, Wei-Kan

    1995-01-01

    Hybrid superconductor magnet bearings (HSMB's) utilize high temperature superconductors (HTS's) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS's, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, we present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  4. Teddy Bear Still Lifes.

    ERIC Educational Resources Information Center

    Mannlein, Sally

    2001-01-01

    Describes an art activity for first-grade students in which the students draw their own still-life pictures, using teddy bears and balls as the subject matter. Explains that the students must include three objects, a line for the table, and overlap the shapes. (CMK)

  5. Teddy bear clinic.

    PubMed

    Creedon, C M

    1989-02-01

    1. The Shriners Institute in Boston developed a day to educate children about hospitals and the OR environment. 2. OR nurses have instituted extensive procedures and policies to allow potential patients the information they need to know their rights. 3. The most important instruction was for the children to ask those questions that they thought their teddy bears might ask.

  6. The Teddy Bears' Disc.

    ERIC Educational Resources Information Center

    Laurillard, Diana

    1985-01-01

    Reports an evaluation of the Teddy Bear disc, an interactive videodisc developed at the Open University for a second-level course in metallurgy and materials technology. Findings from observation of students utilizing the videodisc are reviewed; successful design features and design problems are considered; and development costs are outlined. (MBR)

  7. Optimal Synchronizability of Bearings

    NASA Astrophysics Data System (ADS)

    Araújo, N. A. M.; Seybold, H.; Baram, R. M.; Herrmann, H. J.; Andrade, J. S., Jr.

    2013-02-01

    Bearings are mechanical dissipative systems that, when perturbed, relax toward a synchronized (bearing) state. Here we find that bearings can be perceived as physical realizations of complex networks of oscillators with asymmetrically weighted couplings. Accordingly, these networks can exhibit optimal synchronization properties through fine-tuning of the local interaction strength as a function of node degree [Motter, Zhou, and Kurths, Phys. Rev. E 71, 016116 (2005)PLEEE81539-3755]. We show that, in analogy, the synchronizability of bearings can be maximized by counterbalancing the number of contacts and the inertia of their constituting rotor disks through the mass-radius relation, m˜rα, with an optimal exponent α=α× which converges to unity for a large number of rotors. Under this condition, and regardless of the presence of a long-tailed distribution of disk radii composing the mechanical system, the average participation per disk is maximized and the energy dissipation rate is homogeneously distributed among elementary rotors.

  8. Magnetic Bearings For Turbopumps

    NASA Technical Reports Server (NTRS)

    Meeks, Crawford R.; Mendez, Antonio J.

    1995-01-01

    Report presents study of feasibility of magnetic bearings in turbopumps. Liquid-oxygen turbopump in space shuttle main engine selected for study. Other potential applications include manned and unmanned spacecraft, gas turbines for commercial and military aircraft, turbomachinery for petro-chemical and gas operations, suspension systems for precise machinery, and precise pointing and tracking systems.

  9. Hybrid superconductor magnet bearings

    NASA Technical Reports Server (NTRS)

    Chu, Wei-Kan

    1995-01-01

    Hybrid superconductor magnet bearings (HSMB's) utilize high temperature superconductors (HTS's) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS's, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, we present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  10. Lung transplantation

    PubMed Central

    Afonso, José Eduardo; Werebe, Eduardo de Campos; Carraro, Rafael Medeiros; Teixeira, Ricardo Henrique de Oliveira Braga; Fernandes, Lucas Matos; Abdalla, Luis Gustavo; Samano, Marcos Naoyuki; Pêgo-Fernandes, Paulo Manuel

    2015-01-01

    ABSTRACT Lung transplantation is a globally accepted treatment for some advanced lung diseases, giving the recipients longer survival and better quality of life. Since the first transplant successfully performed in 1983, more than 40 thousand transplants have been performed worldwide. Of these, about seven hundred were in Brazil. However, survival of the transplant is less than desired, with a high mortality rate related to primary graft dysfunction, infection, and chronic graft dysfunction, particularly in the form of bronchiolitis obliterans syndrome. New technologies have been developed to improve the various stages of lung transplant. To increase the supply of lungs, ex vivo lung reconditioning has been used in some countries, including Brazil. For advanced life support in the perioperative period, extracorporeal membrane oxygenation and hemodynamic support equipment have been used as a bridge to transplant in critically ill patients on the waiting list, and to keep patients alive until resolution of the primary dysfunction after graft transplant. There are patients requiring lung transplant in Brazil who do not even come to the point of being referred to a transplant center because there are only seven such centers active in the country. It is urgent to create new centers capable of performing lung transplantation to provide patients with some advanced forms of lung disease a chance to live longer and with better quality of life. PMID:26154550

  11. Lung Diseases

    MedlinePlus

    When you breathe, your lungs take in oxygen from the air and deliver it to the bloodstream. The cells in your body need oxygen to ... you breathe nearly 25,000 times. People with lung disease have difficulty breathing. Millions of people in ...

  12. Lung Cancer

    MedlinePlus

    Lung cancer is one of the most common cancers in the world. It is a leading cause of cancer death in men and women in the United States. Cigarette smoking causes most lung cancers. The more cigarettes you smoke per day and ...

  13. Cilia Dysfunction in Lung Disease

    PubMed Central

    Tilley, Ann E.; Walters, Matthew S.; Shaykhiev, Renat; Crystal, Ronald G.

    2015-01-01

    A characteristic feature of the human airway epithelium is the presence of ciliated cells bearing motile cilia, specialized cell surface projections containing axonemes comprised of microtubules and dynein arms, which provide ATP-driven motility. In the airways, cilia function in concert with airway mucus to mediate the critical function of mucociliary clearance, cleansing the airways of inhaled particles and pathogens. The prototypical disorder of respiratory cilia is primary ciliary dyskinesia, an inherited disorder that leads to impaired mucociliary clearance, repeated chest infections, and progressive destruction of lung architecture. Numerous acquired lung diseases are also marked by abnormalities in both cilia structure and function. In this review we summarize current knowledge regarding airway ciliated cells and cilia, how they function to maintain a healthy epithelium, and how disorders of cilia structure and function contribute to inherited and acquired lung disease. PMID:25386990

  14. Magnetic-Bearing Test Fixture

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J.; Poole, William L.

    1991-01-01

    Microcomputer-controlled magnetic-bearing test fixture used to develop approaches to design of controls for magnetic bearing actuators designed and constructed. Includes load cells connected to bar, in turn, connected through screw positioners to geared drive motors. Position of equivalent suspended element sensed by position sensors and controlled by drive motors. Provides control of gap in magnetic bearing and of current in electromagnet coil. Measurements made include magnetic-bearing gaps, magnetic flux in bearing gaps, and bearing forces. Approaches to linearization and control developed by use of fixture applicable to wide range of small-gap suspension systems.

  15. Flexure Bearing Reduces Startup Friction

    NASA Technical Reports Server (NTRS)

    Clingman, W. Dean

    1991-01-01

    Design concept for ball bearing incorporates small pieces of shim stock, wire spokes like those in bicycle wheels, or other flexing elements to reduce both stiction and friction slope. In flexure bearing, flexing elements placed between outer race of ball bearing and outer ring. Elements flex when ball bearings encounter small frictional-torque "bumps" or even larger ones when bearing balls encounter buildups of grease on inner or outer race. Flexure of elements reduce high friction slopes of "bumps", helping to keep torque between outer ring and inner race low and more nearly constant. Concept intended for bearings in gimbals on laser and/or antenna mirrors.

  16. Bearing-Cartridge Damping Seal

    NASA Technical Reports Server (NTRS)

    Goggins, David G.; Scharrer, Joseph K.; Chen, Wei C.

    1991-01-01

    In proposed design for improved ball-bearing cartridge, damping seal in form of thin-layer fluid journal bearing incorporated into cartridge. Damping seal acts as auxiliary bearing, relieving bearing balls of significant portions of both static and dynamic bearing loads. Damping from seal reduces dynamic loads even further by reducing amplitude of vibrations in second vibrational mode of rotor, which mode occurs when rotor turning at nearly full operating speed. Intended for use in high-pressure-oxygen turbopump of Space Shuttle main engine, also applicable to other turbomachinery bearings.

  17. Lubricant effects on bearing life

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1986-01-01

    Lubricant considerations for rolling-element bearings have within the last two decades taken on added importance in the design and operation of mechanical systems. The phenomenon which limits the useful life of bearings is rolling-element or surface pitting fatigue. The elastohydrodynamic (EHD) film thickness which separates the ball or roller surface from those of the raceways of the bearing directly affects bearing life. Chemical additives added to the lubricant can also significantly affect bearings life and reliability. The interaction of these physical and chemical effects is important to the design engineer and user of these systems. Design methods and lubricant selection for rolling-element bearings are presented and discussed.

  18. What Is Lung Cancer?

    MedlinePlus

    ... Graphics Infographic Stay Informed Cancer Home What Is Lung Cancer? Language: English Español (Spanish) Recommend on Facebook Tweet ... cancer starts in the lungs, it is called lung cancer. Lung cancer begins in the lungs and may ...

  19. Lung Cancer Screening

    MedlinePlus

    ... Treatment Lung Cancer Prevention Lung Cancer Screening Research Lung Cancer Screening (PDQ®)–Patient Version What is screening? ... These are called diagnostic tests . General Information About Lung Cancer Key Points Lung cancer is a disease ...

  20. Lung Cancer Prevention

    MedlinePlus

    ... Treatment Lung Cancer Prevention Lung Cancer Screening Research Lung Cancer Prevention (PDQ®)–Patient Version What is prevention? ... to keep cancer from starting. General Information About Lung Cancer Key Points Lung cancer is a disease ...

  1. Vygotsky and the Three Bears

    ERIC Educational Resources Information Center

    Kulczewski, Peggy

    2004-01-01

    Peggy Kulczewski, a kindergarten classroom teacher, remembers the day when students enjoyed a story she told them from the book "The Three Bears". The students' discussion about comparison of the bears was very helpful to the whole group.

  2. Compliant hydrodynamic fluid journal bearing

    NASA Technical Reports Server (NTRS)

    Warren, E. L. (Inventor)

    1985-01-01

    An air bearing structure is described that prevents destructive bending moments within the top foil. Welds are eliminated by mounting the top bearing foil in the bearing cartridge sleeve without using a space block. Tabs or pins at the end of the top bearing foil are restrained by slots or stops formed in the cartridge sleeve. These structural members are free to move in a direction normal to the shaft while being restrained from movement in the direction of shaft rotation.

  3. Externally Pressurized Journal Gas Bearings

    NASA Technical Reports Server (NTRS)

    Laub, John H.

    1959-01-01

    Externally pressurized gas-lubricated bearings with multiple orifice feed are investigated. An analytical treatment is developed for a semi-cylindrical bearing with 9 orifices and for a cylindrical journal bearing with 192 radial and 24 axial orifices. Experiments are described on models of the two bearing configurations with specially designed fixtures which incorporate pneumatic loading and means for determining pressure profiles, gas flow and gap height. The correlation between theory and experiment is satisfactory.

  4. A self-lubricating bearing

    NASA Technical Reports Server (NTRS)

    Whitaker, A. F. (Inventor)

    1974-01-01

    An improved bearing structure is described which includes a permanently magnetized porous body filled with an interstitial magnetic lubricant for extending the operational life of self-lubricating bearings. The bearing structure is characterized by a permanently magnetized retainer formed of a porous material and filled with an interstitial magnetic lubricant, whereby the pores serve as lubricant reservoirs from which the lubricant continuously is delivered to a film disposed between contiguous bearing surfaces.

  5. Magnetic bearing and motor

    NASA Technical Reports Server (NTRS)

    Studer, Philip A. (Inventor)

    1983-01-01

    A magnetic bearing assembly (10) has an intermediate rotatable section (33) having an outer cylindrical member (30) coaxially suspended by a torsion wire (72) around an axially polarized cylindrical magnet (32). Axial alignment between the pole faces (40-43) of the intermediate section (33) and end surfaces (50-53) of opposed end bells (20, 22) provides a path of least reluctance across intervening air gaps (60-63) for the magnetic flux emanating from magnet (32). Radial dislocation increases the reluctance and creates a radial restoring force. Substitution of radially polarized magnets 107 fixed to a magnetically permeable cylinder (32') and insertion of pairs of armature coil windings (109-112) between the cylinder pair (33') provides an integral magnetic bearing and torsion motor (100) able to provide arcuately limited rotational drive.

  6. Passive magnetic bearing system

    DOEpatents

    Post, Richard F.

    2014-09-02

    An axial stabilizer for the rotor of a magnetic bearing provides external control of stiffness through switching in external inductances. External control also allows the stabilizer to become a part of a passive/active magnetic bearing system that requires no external source of power and no position sensor. Stabilizers for displacements transverse to the axis of rotation are provided that require only a single cylindrical Halbach array in its operation, and thus are especially suited for use in high rotation speed applications, such as flywheel energy storage systems. The elimination of the need of an inner cylindrical array solves the difficult mechanical problem of supplying support against centrifugal forces for the magnets of that array. Compensation is provided for the temperature variation of the strength of the magnetic fields of the permanent magnets in the levitating magnet arrays.

  7. Centrifugally decoupling touchdown bearings

    DOEpatents

    Post, Richard F

    2014-06-24

    Centrifugally decoupling mechanical bearing systems provide thin tensioned metallic ribbons contained in a support structure. This assembly rotates around a stationary shaft being centered at low speeds by the action of the metal ribbons. Tension springs are connected on one end to the ribbons and on the other end to the support structure. The ribbons pass through slots in the inner ring of the support structure. The spring preloading thus insures contact (or near-contact) between the ribbons and the shaft at rotation speeds below the transition speed. Above this speed, however, the centrifugal force on the ribbons produces a tensile force on them that exceeds the spring tensile force so that the ribbons curve outward, effectively decoupling them from mechanical contact with the shaft. They still remain, however, in position to act as a touchdown bearing in case of abnormally high transverse accelerations.

  8. Rotating plug bearing and seal

    DOEpatents

    Wade, Elman E.

    1977-01-01

    A bearing and seal structure for nuclear reactors utilizing rotating plugs above the nuclear reactor vessel. The structure permits lubrication of bearings and seals of the rotating plugs without risk of the lubricant draining into the reactor vessel below. The structure permits lubrication by utilizing a rotating outer race bearing.

  9. Highly integrated magnetic bearings

    SciTech Connect

    Buehler, P.; Siegwart, R.; Herzog, R.

    1995-12-31

    Active Magnetic Bearings (AMB) have many advantages, compared to other bearing concepts. However, for many potential applications they are still too complicated and too expensive. In this paper the authors will present a new concept for active magnetic bearings with smaller dimensions, lower power consumption, and lower cost. To achieve this goal the system has been optimized in an overall mechatronic design. This led to new concepts for rotor, magnets, electronics and control. A single chip computer is used to reduce the number of electronic components. The switches of the voltage controlled power amplifier are driven directly by the PWM-unit of the single chip computer. Additionally, also the frequency inverter for the motor is driven directly by the PWM-unit. This leads to a minimum number of electronic components including the emergency power supply provided through energy recovered by the inverter. For development, calibration and error diagnostics a powerful serial link to a PC has been implemented. It works at a speed of 57.6 kBit/s and realizes a direct interface to MATLAB. This new configuration has been successfully applied to a small rotor system spinning at 60,000 rpm.

  10. Magnetic translator bearings

    NASA Technical Reports Server (NTRS)

    Hockney, Richard L. (Inventor); Downer, James R. (Inventor); Eisenhaure, David B. (Inventor); Hawkey, Timothy J. (Inventor); Johnson, Bruce G. (Inventor)

    1990-01-01

    A magnetic bearing system for enabling translational motion includes a carriage and a shaft for movably supporting the carriage; a first magnetic bearing fixed to one of the carriage and shaft and slidably received in a first channel of the other of the carriage and shaft. The first channel is generally U shaped with two side walls and a back wall. The magnetic bearing includes a pair of spaced magnetic pole pieces, each pole piece having a pair of electromagnetic coils mounted on poles on opposite ends of the pole piece proximate the side walls, and a third electromagnetic coil mounted on a pole of the pole piece proximate the backwall; a motion sensor for sensing translational motion along two axes and rotationally about three axes of the carriage and shaft relative to each other; and a correction circuit responsive to the sensor for generating a correction signal to drive the coils to compensate for any misalignment sensed between the carriage and the shaft.

  11. The series hybrid bearing - A new high speed bearing concept.

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.; Fleming, D. P.; Parker, R. J.

    1971-01-01

    The series-hybrid bearing couples a fluid-film bearing with a rolling-element bearing such that the rolling-element bearing inner race runs at a fraction of shaft speed. A series-hybrid bearing was analyzed and experiments were run at thrust loads from 100 to 300 lb and speeds from 4000 to 30,000 rpm. Agreement between theoretical and experimental speed sharing was good. The lowest speed ratio (ratio of ball bearing inner-race speed to shaft speed) obtained was 0.67. This corresponds to an approximate reduction in DN value of 1/3. For a ball bearing in a 3 million DN application, fatigue life would theoretically be improved by a factor as great as 8.

  12. Lung cancer

    MedlinePlus

    ... Sputum test to look for cancer cells Thoracentesis (sampling of fluid buildup around the lung) In most ... quitting, talk with your provider. There are many methods to help you quit, from support groups to ...

  13. Lung Transplant

    MedlinePlus

    ... will recover in the hospital’s intensive care unit (ICU) before moving to a hospital room for one to three weeks. Your doctor may recommend pulmonary rehabilitation after your lung transplant surgery to help you ...

  14. The bear that never was

    USGS Publications Warehouse

    Smith, T.S.; Amstrup, Steven C.; Herrero, Stephen

    2005-01-01

    From campfire stories to sensational books detailing gory attacks, Alaska's bears have long been maligned as deadly marauders capable of acquiring a taste for human flesh. Tall tales make for good storytelling but force bad reputations on the bears. When myth is compared to fact, the three North American's leading bear experts show that Alaska's three bear species are not the huge, unpredictable monsters they often are made out to be. Here, Smith, Amstrup, and Herrero examine the conventional wisdom people often hear regarding bears in the Great Land.

  15. Bearing for liquid metal pump

    DOEpatents

    Dickinson, Robert J.; Wasko, John; Pennell, William E.

    1984-01-01

    A liquid metal pump bearing support comprises a series of tangentially oriented spokes that connect the bearing cylinder to the pump internals structure. The spokes may be arranged in a plurality of planes extending from the bearing cylinder to the pump internals with the spokes in one plane being arranged alternately with those in the next plane. The bearing support structure provides the pump with sufficient lateral support for the bearing structure together with the capability of accommodating differential thermal expansion without adversely affecting pump performance.

  16. Designing the brawny gas bearing.

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.

    1971-01-01

    Discussion of a graphic technique for matching specific groove parameters to operating conditions in order to optimize the load carrying capacity of a herringbone-grooved bearing. Details are given on the optimization of the film thickness ratio, the groove width ratio, the groove angle, and the groove length ratio to obtain a maximum radial load capacity. The effect of the dimensionless bearing number on optimal groove configuration parameters is shown in diagrams. Curves are also plotted to compare the capacities of a herringbone-grooved bearing and a plain bearing, showing the former has a higher load capacity than the latter when the dimensionless bearing number is large.

  17. Bearing, gearing, and lubrication technology

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.

    1978-01-01

    Results of selected NASA research programs on rolling-element and fluid-film bearings, gears, and elastohydrodynamic lubrication are reported. Advances in rolling-element bearing material technology, which have resulted in a significant improvement in fatigue life, and which make possible new applications for rolling bearings, are discussed. Research on whirl-resistant, fluid-film bearings, suitable for very high-speed applications, is discussed. An improved method for predicting gear pitting life is reported. An improved formula for calculating the thickness of elastohydrodynamic films (the existence of which help to define the operating regime of concentrated contact mechanisms such as bearings, gears, and cams) is described.

  18. Hybrid Bearing Prognostic Test Rig

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Certo, Joseph M.; Handschuh, Robert F.; Dimofte, Florin

    2005-01-01

    The NASA Glenn Research Center has developed a new Hybrid Bearing Prognostic Test Rig to evaluate the performance of sensors and algorithms in predicting failures of rolling element bearings for aeronautics and space applications. The failure progression of both conventional and hybrid (ceramic rolling elements, metal races) bearings can be tested from fault initiation to total failure. The effects of different lubricants on bearing life can also be evaluated. Test conditions monitored and recorded during the test include load, oil temperature, vibration, and oil debris. New diagnostic research instrumentation will also be evaluated for hybrid bearing damage detection. This paper summarizes the capabilities of this new test rig.

  19. Anti-backlash gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2009-01-01

    A gear bearing having a first gear and a second gear, each having a plurality of teeth. Each gear operates on two non-parallel surfaces of the opposing gear teeth to perform both gear and bearing functions simultaneously. The gears are moving at substantially the same speed at their contact points. The gears may be roller gear bearings or phase-shifted gear bearings, and may be arranged in a planet/sun system or used as a transmission. One preferred embodiment discloses and describes an anti-backlash feature to counter ''dead zones'' in the gear bearing movement.

  20. Unexpandable lung.

    PubMed

    Pereyra, Marco F; Ferreiro, Lucía; Valdés, Luis

    2013-02-01

    Unexpandable lung is a mechanical complication by which the lung does not expand to the chest wall, impeding a normal apposition between the two pleural layers. The main mechanism involved is the restriction of the visceral pleura due to the formation of a fibrous layer along this pleural membrane. This happens because of the presence of an active pleural disease (lung entrapment), which can be resolved if proper therapeutic measures are taken, or a remote disease (trapped lung), in which an irreversible fibrous pleural layer has been formed. The clinical suspicion arises with the presence of post-thoracocentesis hydropneumothorax or a pleural effusion that cannot be drained due to the appearance of thoracic pain. The diagnosis is based on the analysis of the pleural liquid, the determination of pleural pressures as we drain the effusion and on air-contrast chest CT. As both represent the continuity of one same process, the results will depend on the time at which these procedures are done. If, when given a lung that is becoming entrapped, the necessary therapeutic measures are not taken, the final result will be a trapped lung. In this instance, most patients are asymptomatic or have mild exertional dyspnea and therefore they do not require treatment. Nevertheless, in cases of incapacitating dyspnea, it may be necessary to use pleural decortication in order to resolve the symptoms. Copyright © 2012 SEPAR. Published by Elsevier Espana. All rights reserved.

  1. Amino acid metabolism in tumour-bearing mice.

    PubMed Central

    Rivera, S; Azcón-Bieto, J; López-Soriano, F J; Miralpeix, M; Argilés, J M

    1988-01-01

    Mice bearing the Lewis lung carcinoma showed a high tumour glutaminase activity and significantly higher concentrations of most amino acids than in both the liver and the skeletal muscle of the host. Tumour tissue slices showed a marked preference for glutamine, especially for oxidation of its skeleton to CO2. It is proposed that the metabolism of this particular carcinoma is focused on amino acid degradation, glutamine being its preferred substrate. PMID:3342022

  2. Bearing construction for refrigeration compresssor

    DOEpatents

    Middleton, Marc G.; Nelson, Richard T.

    1988-01-01

    A hermetic refrigeration compressor has a cylinder block and a crankshaft rotatable about a vertical axis to reciprocate a piston in a cylinder on the cylinder block. A separate bearing housing is secured to the central portion of the cylinder block and extends vertically along the crankshaft, where it carries a pair of roller bearings to journal the crankshaft. The crankshaft has a radially extending flange which is journaled by a thrust-type roller bearing above the bearing housing to absorb the vertical forces on the crankshaft so that all three of the roller bearings are between the crankshaft and the bearing housing to maintain and control the close tolerances required by such bearings.

  3. Effect of Bearing Cleaning on Long Term Bearing Life

    NASA Technical Reports Server (NTRS)

    Jett, Tim; Thom, R. L.

    1999-01-01

    For many years chlorofluorocarbon (CFC) based solvents, such as CFC-113 and 1,1,1, trichloroethane (TCA), were used as bearing cleaning solvents for space mechanism bearings. The 1995 ban on the production of ozone depleting chemicals (ODC) such as CFCs caused a change requiring the use of ODC-free cleaners for precision bearing cleaning. With this change the question arises; what effect if any do these new cleaners have on long term bearing life? The purpose of this study was to evaluate this effect. A one year test using 60 small electrical motors (two bearings per motor) was conducted in a high vacuum environment (2.0 x 10(exp -6) torr) at a temperature of 90 C. Prior to testing the bearings were cleaned with one of four cleaners. These cleaners included two aqueous based cleaners, a CFC based cleaner and supercritical carbon dioxide. Three space compatible greases were tested. After testing, the mass of each lubricated bearing was measured both pre and post test. Along with mass loss measurements a profilometer trace of each bearing was taken to measure post test wear of the bearings. In addition, the bearings were visually examined and analyzed using an optical microscope.

  4. Introgressive hybridization: brown bears as vectors for polar bear alleles.

    PubMed

    Hailer, Frank

    2015-03-01

    The dynamics and consequences of introgression can inform about numerous evolutionary processes. Biologists have therefore long been interested in hybridization. One challenge, however, lies in the identification of nonadmixed genotypes that can serve as a baseline for accurate quantification of admixture. In this issue of Molecular Ecology, Cahill et al. (2015) analyse a genomic data set of 28 polar bears, eight brown bears and one American black bear. Polar bear alleles are found to be introgressed into brown bears not only near a previously identified admixture zone on the Alaskan Admiralty, Baranof and Chichagof (ABC) Islands, but also far into the North American mainland. Elegantly contrasting admixture levels at autosomal and X chromosomal markers, Cahill and colleagues infer that male-biased dispersal has spread these introgressed alleles away from the Late Pleistocene contact zone. Compared to a previous study on the ABC Island population in which an Alaskan brown bear served as a putatively admixture-free reference, Cahill et al. (2015) utilize a newly sequenced Swedish brown bear as admixture baseline. This approach reveals that brown bears have been impacted by introgression from polar bears to a larger extent (up to 8.8% of their genome), than previously known, including the bear that had previously served as admixture baseline. No evidence for introgression of brown bear into polar bear is found, which the authors argue could be a consequence of selection. Besides adding new exciting pieces to the puzzle of polar/brown bear evolutionary history, the study by Cahill and colleagues highlights that wildlife genomics is moving from analysing single genomes towards a landscape genomics approach. © 2015 John Wiley & Sons Ltd.

  5. Gold-bearing skarns

    USGS Publications Warehouse

    Theodore, Ted G.; Orris, Greta J.; Hammerstrom, Jane M.; Bliss, James D.

    1991-01-01

    In recent years, a significant proportion of the mining industry's interest has been centered on discovery of gold deposits; this includes discovery of additional deposits where gold occurs in skarn, such as at Fortitude, Nevada, and at Red Dome, Australia. Under the classification of Au-bearing skarns, we have modeled these and similar gold-rich deposits that have a gold grade of at least 1 g/t and exhibit distinctive skarn mineralogy. Two subtypes, Au-skarns and byproduct Au-skarns, can be recognized on the basis of gold, silver, and base-metal grades, although many other geological factors apparently are still undistinguishable largely because of a lack of detailed studies of the Au-skarns. Median grades and tonnage for 40 Au-skarn deposits are 8.6 g/t Au, 5.0 g/t Ag, and 213,000 t. Median grades and tonnage for 50 byproduct and Au-skarn deposits are 3.7 g/t Au, 37 g/t Ag, and 330,000 t. Gold-bearing skarns are generally calcic exoskarns associated with intense retrograde hydrosilicate alteration. These skarns may contain economic amounts of numerous other commodities (Cu, Fe, Pb, Zn, As, Bi, W, Sb, Co, Cd, and S) as well as gold and silver. Most Au-bearing skarns are found in Paleozoic and Cenozoic orogenic-belt and island-arc settings and are associated with felsic to intermediate intrusive rocks of Paleozoic to Tertiary age. Native gold, electru, pyrite, pyrrhotite, chalcopyrite, arsenopyrite, sphalerite, galena, bismuth minerals, and magnetite or hematite are the most common opaque minerals. Gangue minerals typically include garnet (andradite-grossular), pyroxene (diopside-hedenbergite), wollastonite, chlorite, epidote, quartz, actinolite-tremolite, and (or) calcite.

  6. Bearing Restoration by Grinding

    DTIC Science & Technology

    1976-05-21

    with x-ray diffraction measurement. 4.4 Hardness 4.4.1 Hardness tests shall be conducted in accordance with ASTM E18 . 4.5 Surfane Finish 4.5.1 Surface...STA14DARDS INSTITUTE ANSI B46.1 Surface Texture AMERICAN SOCIETY FOR TESTING MATERIALS ASTrd E18 Rockwell Hardness and Rockwell Superficial Hardness of...Metallic Materials ASTM E112 Average Grain Size of Metals .. MILITARY MIL-B-197 Bearing, Rolling element, associated parts 3. REQUIREMENTS 3. 1

  7. Description of a magnetic bearing test fixture

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J.; Poole, William L.

    1987-01-01

    A description of a microcomputer controlled magnetic bearing test fixture is presented. Parameters which are controlled are magnetic bearing current and gaps. Parameters which are measured are magnetic bearing gaps, magnetic flux in the bearing gaps, and bearing forces. The test fixture is configured for bearing elements similar to those used in a laboratory test model Annular Momentum Control Device (AMCD).

  8. Development of hybrid bearing system with thrust superconducting magnetic bearing and radial active electromagnetic bearing

    NASA Astrophysics Data System (ADS)

    Nicolsky, R.; Pereira, A. S.; de Andrade, R.; David, D. F. B.; Santisteban, J. A.; Stephan, R. M.; Ripper, A.; Gawalek, W.; Habisreuther, T.; Strasser, T.

    A superconducting/electromagnetic hybrid bearing system is currently under development and test. This system consists of a thrust superconducting magnetic bearing and a double radial active electromagnetic bearing/motor devices. The thrust bearing has been designed using NdFeB permanent magnets levitating on a set of superconducting monoliths of YBCO, prepared by top seeded melt texturing technique, which supports the weight of the rotor. The bearing/motor devices were conceived as 4-pole 2-phase induction machine using stator windings for delivering torque and radial positioning simultaneously. Using this superconducting axial bearing and the active bearings for the rotor radial positioning, a fully levitating vertical-shaft inductive machine has been tested. The tests were successful in reaching a controlled levitation up to 6,300 rpm.

  9. Aerospace applications of magnetic bearings

    NASA Technical Reports Server (NTRS)

    Downer, James; Goldie, James; Gondhalekar, Vijay; Hockney, Richard

    1994-01-01

    Magnetic bearings have traditionally been considered for use in aerospace applications only where performance advantages have been the primary, if not only, consideration. Conventional wisdom has been that magnetic bearings have certain performance advantages which must be traded off against increased weight, volume, electric power consumption, and system complexity. These perceptions have hampered the use of magnetic bearings in many aerospace applications because weight, volume, and power are almost always primary considerations. This paper will review progress on several active aerospace magnetic bearings programs at SatCon Technology Corporation. The magnetic bearing programs at SatCon cover a broad spectrum of applications including: a magnetically-suspended spacecraft integrated power and attitude control system (IPACS), a magnetically-suspended momentum wheel, magnetic bearings for the gas generator rotor of a turboshaft engine, a vibration-attenuating magnetic bearing system for an airborne telescope, and magnetic bearings for the compressor of a space-rated heat pump system. The emphasis of these programs is to develop magnetic bearing technologies to the point where magnetic bearings can be truly useful, reliable, and well tested components for the aerospace community.

  10. Aerospace applications of magnetic bearings

    NASA Astrophysics Data System (ADS)

    Downer, James; Goldie, James; Gondhalekar, Vijay; Hockney, Richard

    1994-05-01

    Magnetic bearings have traditionally been considered for use in aerospace applications only where performance advantages have been the primary, if not only, consideration. Conventional wisdom has been that magnetic bearings have certain performance advantages which must be traded off against increased weight, volume, electric power consumption, and system complexity. These perceptions have hampered the use of magnetic bearings in many aerospace applications because weight, volume, and power are almost always primary considerations. This paper will review progress on several active aerospace magnetic bearings programs at SatCon Technology Corporation. The magnetic bearing programs at SatCon cover a broad spectrum of applications including: a magnetically-suspended spacecraft integrated power and attitude control system (IPACS), a magnetically-suspended momentum wheel, magnetic bearings for the gas generator rotor of a turboshaft engine, a vibration-attenuating magnetic bearing system for an airborne telescope, and magnetic bearings for the compressor of a space-rated heat pump system. The emphasis of these programs is to develop magnetic bearing technologies to the point where magnetic bearings can be truly useful, reliable, and well tested components for the aerospace community.

  11. Effect of Bearing Cleaning on Long Term Bearing Life

    NASA Technical Reports Server (NTRS)

    Jett, Timothy Raymond; Thom, Robert L.

    1998-01-01

    For many years chlorofluorocarbon (CFC ) based solvents, such as Freon and 1,1,1, Trichloroethane (TCA), were used as bearing cleaning solvents for space mechanisms. The 1995 ban on the production of ozone depleting chemicals (ODC) such as CFCs caused a change to new ODC-free cleaners for the precision bearing cleaning. With this change the question arises what effect if any do these new cleaners have on long term bearing life. The purpose of this study was to evaluate this effect. A one year test using 60 small electrical motors (two bearings per motor) was conducted in a high vacuum environment (2.0* 10(exp -6) torr) at a temperature of 90C. Prior to testing the bearings were cleaned with one of four cleaners. These cleaners included two aqueous based cleaners, a CFC based cleaner and supercritical carbon dioxide. Three space compatible greases were tested. After testing the mass of each lubricated bearing was measured both pre and post test. Along with mass loss measurements a profilometer trace of each bearing was taken to measure post test wear of the bearings. In addition the bearings were visually examined and analyzed using an optical microscope.

  12. Effect of Bearing Cleaning on Long Term Bearing Life

    NASA Technical Reports Server (NTRS)

    Jett, Timothy Raymond; Thom, Robert L.

    1998-01-01

    For many years chlorofluorocarbon (CFC ) based solvents, such as Freon and 1,1,1, Trichloroethane (TCA), were used as bearing cleaning solvents for space mechanisms. The 1995 ban on the production of ozone depleting chemicals (ODC) such as CFCs caused a change to new ODC-free cleaners for the precision bearing cleaning. With this change the question arises what effect if any do these new cleaners have on long term bearing life. The purpose of this study was to evaluate this effect. A one year test using 60 small electrical motors (two bearings per motor) was conducted in a high vacuum environment (2.0* 10(exp -6) torr) at a temperature of 90C. Prior to testing the bearings were cleaned with one of four cleaners. These cleaners included two aqueous based cleaners, a CFC based cleaner and supercritical carbon dioxide. Three space compatible greases were tested. After testing the mass of each lubricated bearing was measured both pre and post test. Along with mass loss measurements a profilometer trace of each bearing was taken to measure post test wear of the bearings. In addition the bearings were visually examined and analyzed using an optical microscope.

  13. Reduction in bearing size due to superconductors in magnetic bearings

    NASA Technical Reports Server (NTRS)

    Rao, Dantam K.; Lewis, Paul; Dill, James F.

    1991-01-01

    A design concept that reduces the size of magnetic bearings is assessed. The small size will enable magnetic bearings to fit into limited available bearing volume of cryogenic machinery. The design concept, called SUPERC, uses (high Tc) superconductors or high-purity aluminum conductors in windings instead of copper. The relatively high-current density of these conductors reduces the slot radial thickness for windings, which reduces the size of the bearings. MTI developed a sizing program called SUPERC that translates the high-current density of these conductors into smaller sized bearings. This program was used to size a superconducting bearing to carry a 500 lb. load. The sizes of magnetic bearings needed by various design concepts are as follows: SUPERC design concept = 3.75 in.; magnet-bias design concept = 5.25 in.; and all electromagnet design concept = 7.0 in. These results indicate that the SUPERC design concept can significantly reduce the size of the bearing. This reduction, in turn, reduces the weight and yields a lighter bearing. Since the superconductors have inherently near-zero resistance, they are also expected to save power needed for operation considerably.

  14. Rheumatoid lung disease

    MedlinePlus

    Lung disease - rheumatoid arthritis; Rheumatoid nodules; Rheumatoid lung ... Lung problems are common in rheumatoid arthritis. They often cause no symptoms. The cause of lung disease associated with rheumatoid arthritis is unknown. Sometimes, the medicines used to ...

  15. Nutrition for Lung Cancer

    MedlinePlus

    ... by zip code or Select your state State Lung Cancer www.lung.org > Lung Health and Diseases > ... I Stay Healthy Share this page: Nutrition for Lung Cancer Key Points There is no prescribed diet ...

  16. Lung Nodules: Overview

    MedlinePlus

    ... Research & Science Education & Training Home Conditions Lung Nodules Lung Nodules Make an Appointment Find a Doctor Ask ... Kern, MD (June 01, 2016) What is a lung nodule? A lung nodule is also called a ...

  17. Eosinophilic Lung Disorders

    MedlinePlus

    ... Education & Training Home Conditions Eosinophilic Lung Disorders Eosinophilic Lung Disorders Make an Appointment Find a Doctor Ask ... Rafeul Alam, MD, PhD (July 01, 2012) Eosinophilic lung disorders are a category of lung problems characterized ...

  18. Lung Nodules: Overview

    MedlinePlus

    ... Research & Science Education & Training Home Conditions Lung Nodules Lung Nodules Make an Appointment Find a Doctor Ask ... Kern, MD (June 01, 2016) What is a lung nodule? A lung nodule is also called a ...

  19. Lung Cancer Screening

    MedlinePlus

    Lung cancer screening Overview By Mayo Clinic Staff Lung cancer screening is a process that's used to detect the presence ... with a high risk of lung cancer. Lung cancer screening is recommended for older adults who are longtime ...

  20. Lung cancer - small cell

    MedlinePlus

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC are ...

  1. Furrier's lung

    PubMed Central

    Pimentel, J. Cortez

    1970-01-01

    As is known, the inhalation of animal hairs can provoke immunological reactions in the respiratory tract affecting the naso-tracheo-bronchial sector and giving rise to asthma-like syndromes. Another form of disease, found in furriers with long exposure to `hair dust', is described. It is characterized by a granulomatous interstitial pneumonia, of the tuberculoid type, very similar to that described in other diseases related to the inhalation of organic dusts, both vegetable and animal, such as `farmer's lung' and `bird fancier's lung'. This new disease—which we experimentally reproduced—can be diagnosed from the occupational history together with the finding on lung biopsy of hair shafts within granulomatous lesions (birefringence and histo-chemical reactions). As in other diseases of this type, a host factor of probable immunological nature is suggested. Attention is drawn to the need to protect workers in the furrier's trade. Images PMID:5484998

  2. Tsunami lung.

    PubMed

    Inoue, Yoshihiro; Fujino, Yasuhisa; Onodera, Makoto; Kikuchi, Satoshi; Shozushima, Tatsuyori; Ogino, Nobuyoshi; Mori, Kiyoshi; Oikawa, Hirotaka; Koeda, Yorihiko; Ueda, Hironobu; Takahashi, Tomohiro; Terui, Katsutoshi; Nakadate, Toshihide; Aoki, Hidehiko; Endo, Shigeatsu

    2012-04-01

    We encountered three cases of lung disorders caused by drowning in the recent large tsunami that struck following the Great East Japan Earthquake. All three were females, and two of them were old elderly. All segments of both lungs were involved in all the three patients, necessitating ICU admission and endotracheal intubation and mechanical ventilation. All three died within 3 weeks. In at least two cases, misswallowing of oil was suspected from the features noted at the time of the detection. Sputum culture for bacteria yielded isolation of Stenotrophomonas maltophilia, Legionella pneumophila, Burkholderia cepacia, and Pseudomonas aeruginosa. The cause of tsunami lung may be a combination of chemical induced pneumonia and bacterial pneumonia.

  3. Lung imaging.

    PubMed

    Ley, Sebastian

    2015-06-01

    Imaging of the lung is a mainstay of respiratory medicine. It provides local information about morphology and function of the lung parenchyma that is unchallenged by other noninvasive techniques. During the 2014 European Respiratory Society International Congress in Munich, Germany, a Clinical Year in Review session was held focusing on the latest developments in pulmonary imaging. This review summarises some of the main findings of peer-reviewed articles that were published in the 12-month period prior to the 2014 International Congress. Copyright ©ERS 2015.

  4. Prototype testing of magnetic bearings

    NASA Technical Reports Server (NTRS)

    Plant, David P.; Jayaraman, Chaitanya P.; Frommer, David A.; Kirk, James A.; Anand, Davinder K.

    1987-01-01

    The testing and evaluation of the performance of a magnetic bearing assembly for flywheel energy storage applications are discussed. The experimental set up for determining the passive radial stiffness, active radial stiffness, and curent force sensitivity of the coils follows the method developed by Frommer (1986). Magnetic bearings design should preclude saturation and current limiting in the desired operating range, so that the system will be linear. A larger linear range will lead to a more stable magnetic bearing.

  5. Prototype testing of magnetic bearings

    NASA Technical Reports Server (NTRS)

    Plant, David P.; Jayaraman, Chaitanya P.; Frommer, David A.; Kirk, James A.; Anand, Davinder K.

    1987-01-01

    The testing and evaluation of the performance of a magnetic bearing assembly for flywheel energy storage applications are discussed. The experimental set up for determining the passive radial stiffness, active radial stiffness, and curent force sensitivity of the coils follows the method developed by Frommer (1986). Magnetic bearings design should preclude saturation and current limiting in the desired operating range, so that the system will be linear. A larger linear range will lead to a more stable magnetic bearing.

  6. Robust and intelligent bearing estimation

    DOEpatents

    Claassen, John P.

    2000-01-01

    A method of bearing estimation comprising quadrature digital filtering of event observations, constructing a plurality of observation matrices each centered on a time-frequency interval, determining for each observation matrix a parameter such as degree of polarization, linearity of particle motion, degree of dyadicy, or signal-to-noise ratio, choosing observation matrices most likely to produce a set of best available bearing estimates, and estimating a bearing for each observation matrix of the chosen set.

  7. Evaluation of shuttle turbopump bearings

    NASA Technical Reports Server (NTRS)

    Dufrane, K. F.; Kannel, J. W.

    1978-01-01

    Because the high pressure turbopumps used on the space shuttle main engine (SSME) are high speed machines and rotor dynamics analysis of these units is very complicated, it was considered necessary to verify calculated turbomachinery shaft bearing loads by analysis of ball bearing load tracks. This report presents the methods used and the results of load track analysis on one set of bearings removed from a high pressure liquid oxygen turbopump which had been subjected to SSME static firing tests. This type of analysis was found useful in determining bearing operating conditions and for verifying rotor dynamics computer models.

  8. Series-hybrid bearing - An approach to extending bearing fatigue life at high speeds

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.; Coe, H. H.; Fleming, D. P.; Parker, R. J.

    1971-01-01

    Fluid film bearing of hybrid device consists of orifice compensated annular thrust bearing and self-acting journal bearing. In series hybrid bearing, both ball bearing and annular thrust bearing carry full system thrust load, but two bearings share speed. Operation of system is stable and automatically fail-safe.

  9. The polar bear phenomena

    SciTech Connect

    Maw, P.K. ); Lane, M.T.

    1990-02-01

    Results from measuring the thermal profile of polar bear pelts, reflectiveness of the pelts, and total thermal conversion data lead to the conclusion that the pelts from an ultra-efficient thermal diode for solar-thermal conversion. The transfer of the thermal energy from the surface of the fur to the skin where it is absorbed cannot be thermal, and therefore must be radiative. This process must have an efficiency of better than 90:0090 percent to account for measured values. The radiative transfer process is not known at present. To understand it, a detailed knowledge of the microscopic parameters of the pelts must be obtained. This is the current thrust of the polar solar research. If the process can be understood and synthesized,it will provide a major breakthrough in the area of solar-thermal energy conversion.

  10. Introduction to magnetic bearings

    NASA Technical Reports Server (NTRS)

    Skowronski, Lori; Bisese, Anne

    1993-01-01

    Multi-axis suspension has several advantages over single axis system, in that it provides control of an object with precision in two or three orthogonal axes. In this report, we discuss the primary use of magnetic-bearing suspension and it's relevance to what was formally known as NASA's Annular Suspension and Pointing System (ASPS). This system is an experimental pointing system with applications for the space shuttle and the space station programs. The objectives behind this magnetic suspension research project are to provide insight to the use of the ASPS configuration, to control the solar panels of the space station. This is important to maintain the correct position of the panels in relation to the sun and orbiting space station for the continuous supply of solar energy. Since the panels are suspended, they can be aligned with minimum outside interference. The approach of using magnetic suspension technology guarantees mechanical isolation since there are no contacting surfaces. This isolation reduces vibration transmission and mechanical wear which in turn extends the life of the payload and of the carrier. It should be noted that ASPS has a high pointing accuracy along the line of 0.01 arc-second. This research will be done in a laboratory setting by incorporating five bearing stations and one motion control station. We will attempt to suspend an object of dead weight similar to that of a solar panel. The long term applications may include deep-space navigation, fire control in weapon systems, and an improved mass transit system.

  11. [Humidifier lung].

    PubMed

    Gerber, P; de Haller, R; Pyrozynski, W J; Sturzenegger, E R; Brändli, O

    1981-02-07

    Breathing air from a humidifier or an air conditioning unit contaminated by various microorganisms can cause an acute lung disease involving fever, cough and dyspnea, termed "humidifier fever". This type of hypersensitivity pneumonitis was first described in 1959 by PESTALOZZI in the Swiss literature and subsequently by BANASZAK et al. in the Anglo-American. Here a chronic form of this disease which led to pulmonary fibrosis is described: A 37-year-old woman who works in a cheese shop presented with dyspnea which had been progressive over two years, weight loss, a diffuse reticular pattern radiographically and a severe restrictive defect in lung function tests. Open lung biopsy revealed chronic interstitial and alveolar inflammation with non-caseating granulomas and fibrotic changes. Circulating immune complexes and precipitins against the contaminated humidifier water and cheese mites were found, but no antibodies suggesting legionnaires' disease. Two out of five otherwise healthy employees of this cheese shop, where a new humidifying system had been installed 7 years earlier, also had precipitins against the contaminated water from the humidifier and the cheese mites. Despite ending of exposure and longterm steroid and immunosuppressive therapy, the signs and symptoms of pulmonary fibrosis persisted. Contrary to the acute disease, this chronic form is termed "humidifier lung". The importance is stressed of investigating the possibility of exposure to contaminated humidifiers or air conditioning units in all cases of newly detected pulmonary fibrosis.

  12. What Are Lung Carcinoid Tumors?

    MedlinePlus

    ... Carcinoid Tumor About Lung Carcinoid Tumors What Are Lung Carcinoid Tumors? Lung carcinoid tumors (also known as ... lungs, as well as the neuroendocrine system. The lungs The lungs are 2 sponge-like organs in ...

  13. Permanent-Magnet Meissner Bearing

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    1994-01-01

    Permanent-magnet meissner bearing features inherently stable, self-centering conical configuration. Bearing made stiffer or less stiff by selection of magnets, springs, and spring adjustments. Cylindrical permanent magnets with axial magnetization stacked coaxially on rotor with alternating polarity. Typically, rare-earth magnets used. Magnets machined and fitted together to form conical outer surface.

  14. Spherical-Bearing Analysis Program

    NASA Technical Reports Server (NTRS)

    Kleckner, R. J.

    1984-01-01

    Computer program SPHERBEAN, developed to predict thermomechanical performance characteristics of double-row spherical roller bearings over wide range of operating conditions. Analysis allows six degrees of freedom for each roller and three for each half of an optionally split cage. Program capabilities provide sufficient generality to allow detailed simulation of both high-speed and conventional bearing operation.

  15. Permanent-Magnet Meissner Bearing

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    1994-01-01

    Permanent-magnet meissner bearing features inherently stable, self-centering conical configuration. Bearing made stiffer or less stiff by selection of magnets, springs, and spring adjustments. Cylindrical permanent magnets with axial magnetization stacked coaxially on rotor with alternating polarity. Typically, rare-earth magnets used. Magnets machined and fitted together to form conical outer surface.

  16. Lubrication of rolling element bearings

    NASA Technical Reports Server (NTRS)

    Parker, R. J.

    1980-01-01

    This paper is a broad survey of the lubrication of rolling-element bearings. Emphasis is on the critical design aspects related to speed, temperature, and ambient pressure environment. Types of lubrication including grease, jets, mist, wick, and through-the-race are discussed. The paper covers the historical development, present state of technology, and the future problems of rolling-element bearing lubrication.

  17. Corrosion-Resistant Ball Bearings

    NASA Technical Reports Server (NTRS)

    Zdankiewicz, E. M.; Linaburg, E. L.; Lytle, L. J.

    1990-01-01

    Self-lubricating bearing system withstands highly corrosive environment of wastewater-recycling unit. New bearings contain cobalt-based-alloy balls and races, graphite/polyimide polymer ball cages, and single integral polytetrafluoroethylene seals on wet sides. Materials and design prevent corrosion by acids and provide lubrication.

  18. Geophagy by yellowstone grizzly bears

    USGS Publications Warehouse

    Mattson, D.J.; Green, G.I.; Swalley, R.

    1999-01-01

    We documented 12 sites in the Yellowstone ecosystem where grizzly bears (Ursus arctos horribilis) had purposefully consumed soil (an activity known as geophagy). We also documented soil in numerous grizzly bear feces. Geophagy primarily occurred at sites barren of vegetation where surficial geology had been modified by geothermal activity. There was no evidence of ungulate use at most sites. Purposeful consumption of soil by bears peaked first from March to May and again from August to October, synchronous with peaks in consumption of ungulate meat and mushrooms. Geophageous soils were distinguished from ungulate mineral licks and soils in general by exceptionally high concentrations of potassium (K) and high concentrations of magnesium (Mg) and sulphur (S). Our results do not support the hypotheses that bears were consuming soil to detoxify secondary compounds in grazed foliage, as postulated for primates, or to supplement dietary sodium, as known for ungulates. Our results suggest that grizzly bears could have been consuming soil as an anti-diarrheal.

  19. Nonlinear control of magnetic bearings

    NASA Technical Reports Server (NTRS)

    Pradeep, A. K.; Gurumoorthy, R.

    1994-01-01

    In this paper we present a variety of nonlinear controllers for the magnetic bearing that ensure both stability and robustness. We utilize techniques of discontinuous control to design novel control laws for the magnetic bearing. We present in particular sliding mode controllers, time optimal controllers, winding algorithm based controllers, nested switching controllers, fractional controllers, and synchronous switching controllers for the magnetic bearing. We show existence of solutions to systems governed by discontinuous control laws, and prove stability and robustness of the chosen control laws in a rigorous setting. We design sliding mode observers for the magnetic bearing and prove the convergence of the state estimates to their true values. We present simulation results of the performance of the magnetic bearing subject to the aforementioned control laws, and conclude with comments on design.

  20. Space Station alpha joint bearing

    NASA Technical Reports Server (NTRS)

    Everman, Michael R.; Jones, P. Alan; Spencer, Porter A.

    1987-01-01

    Perhaps the most critical structural system aboard the Space Station is the Solar Alpha Rotary Joint which helps align the power generation system with the sun. The joint must provide structural support and controlled rotation to the outboard transverse booms as well as power and data transfer across the joint. The Solar Alpha Rotary Joint is composed of two transition sections and an integral, large diameter bearing. Alpha joint bearing design presents a particularly interesting problem because of its large size and need for high reliability, stiffness, and on orbit maintability. The discrete roller bearing developed is a novel refinement to cam follower technology. It offers thermal compensation and ease of on-orbit maintenance that are not found in conventional rolling element bearings. How the bearing design evolved is summarized. Driving requirements are reviewed, alternative concepts assessed, and the selected design is described.

  1. Basic Expeditionary Airfield Resources (BEAR) Mission Brief

    DTIC Science & Technology

    2011-11-02

    FL BEAR Holloman AFB, NM Kadena, JP McAlester, OK Diego Garcia Saipan Munitions Storage Location General WRM Storage Location Capabilities • BEAR...Global BEAR Management MSgt Pedro Ramos , Supt, Global BEAR E i t & S (2G MSgt) (Vacant), Global BEAR Systems and Readiness Management (2G MSgt

  2. Effects of bearing cleaning and lube environment on bearing performance

    NASA Technical Reports Server (NTRS)

    Ward, Peter C.

    1995-01-01

    Running torque data of SR6 ball bearings are presented for different temperatures and speeds. The data are discussed in contrast to generally used torque prediction models and point out the need to obtain empirical data in critical applications. Also, the effects of changing bearing washing techniques from old, universally used CFC-based systems to CFC-free aqueous/alkaline solutions are discussed. Data on wettability, torque and lubricant life using SR3 ball bearings are presented. In general, performance is improved using the new aqueous washing techniques.

  3. Crawler Bearing Replacement

    NASA Image and Video Library

    2014-02-28

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, ground support technicians monitor the progress as the B and D truck sections of crawler-transporter 2, or CT-2, are being raised up to prepare for installation of new roller bearing assemblies. Sections of the crawler’s large metal tracks have been removed. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  4. Crawler Bearing Replacement

    NASA Image and Video Library

    2014-02-28

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, a technician monitors the progress as the B and D truck sections of crawler-transporter 2, or CT-2, are raised up to prepare for installation of new roller bearing assemblies. Sections of the crawler’s large metal tracks have been removed. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  5. Crawler Bearing Replacement

    NASA Image and Video Library

    2014-02-28

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, the B and D truck sections of crawler-transporter 2, or CT-2, are being raised up to prepare for installation of new roller bearing assemblies. Sections of the crawler’s large metal tracks have been removed. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  6. Crawler Bearing Replacement

    NASA Image and Video Library

    2014-02-28

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, the B and D truck sections of crawler-transporter 2, or CT-2, have been raised up to prepare for installation of new roller bearing assemblies. Sections of the crawler’s large metal tracks have been removed. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  7. Magnetic Bearings at Draper Laboratory

    NASA Technical Reports Server (NTRS)

    Kondoleon, Anthony S.; Kelleher, William P.; Possel, Peter D.

    1996-01-01

    Magnetic bearings, unlike traditional mechanical bearings, consist of a series of components mated together to form a stabilized system. The correct design of the actuator and sensor will provide a cost effective device with low power requirements. The proper choice of a control system utilizes the variables necessary to control the system in an efficient manner. The specific application will determine the optimum design of the magnetic bearing system including the touch down bearing. Draper for the past 30 years has been a leader in all these fields. This paper summarizes the results carried out at Draper in the field of magnetic bearing development. A 3-D radial magnetic bearing is detailed in this paper. Data obtained from recently completed projects using this design are included. One project was a high radial load (1000 pound) application. The second was a high speed (35,000 rpm), low loss flywheel application. The development of a low loss axial magnetic bearing is also included in this paper.

  8. SSME turbopump bearing analytical study

    NASA Technical Reports Server (NTRS)

    Kannel, J. W.; Merriman, T.

    1980-01-01

    Three shuttle pump bearings operating under severe overspeed and shut-down conditions are evaluated. The specific parameters investigated include outer race stresses, cage stresses, cage-race drag, bearing heating, and crush loading. A quasi-dynamic version of the BASDAP computer code was utilized which involved the calculation of ball-race forces (inner and outer), contact pressures, contact dimensions, and contact angles as a function of (1) axial load, (2) radial load, and (3) centrifugal load on the bearing. Generally, radial loads on the order of 13,300 N (3000 pounds) per bearing or 26,700 N (6000 pounds) per bearing pair, could be expected to cause severe problems to any of the bearings with a 17,800 N (4000 pounds) axial load. Further, when possible temperature excursions are considered, even a load of 8900 N (2000 pounds) may be excessive. However, high momentary radial loads with a 3800 N (850 pounds) axial load would not be anticipated to cause catastrophic failure of the fuel pump bearing.

  9. Fluid Film Bearing Code Development

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The next generation of rocket engine turbopumps is being developed by industry through Government-directed contracts. These turbopumps will use fluid film bearings because they eliminate the life and shaft-speed limitations of rolling-element bearings, increase turbopump design flexibility, and reduce the need for turbopump overhauls and maintenance. The design of the fluid film bearings for these turbopumps, however, requires sophisticated analysis tools to model the complex physical behavior characteristic of fluid film bearings operating at high speeds with low viscosity fluids. State-of-the-art analysis and design tools are being developed at the Texas A&M University under a grant guided by the NASA Lewis Research Center. The latest version of the code, HYDROFLEXT, is a thermohydrodynamic bulk flow analysis with fluid compressibility, full inertia, and fully developed turbulence models. It can predict the static and dynamic force response of rigid and flexible pad hydrodynamic bearings and of rigid and tilting pad hydrostatic bearings. The Texas A&M code is a comprehensive analysis tool, incorporating key fluid phenomenon pertinent to bearings that operate at high speeds with low-viscosity fluids typical of those used in rocket engine turbopumps. Specifically, the energy equation was implemented into the code to enable fluid properties to vary with temperature and pressure. This is particularly important for cryogenic fluids because their properties are sensitive to temperature as well as pressure. As shown in the figure, predicted bearing mass flow rates vary significantly depending on the fluid model used. Because cryogens are semicompressible fluids and the bearing dynamic characteristics are highly sensitive to fluid compressibility, fluid compressibility effects are also modeled. The code contains fluid properties for liquid hydrogen, liquid oxygen, and liquid nitrogen as well as for water and air. Other fluids can be handled by the code provided that the

  10. 49 CFR 229.69 - Side bearings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....69 Side bearings. (a) Friction side bearings with springs designed to carry weight may not have more than 25 percent of the springs in any one nest broken. (b) Friction side bearings may not be run in...

  11. 49 CFR 229.69 - Side bearings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....69 Side bearings. (a) Friction side bearings with springs designed to carry weight may not have more than 25 percent of the springs in any one nest broken. (b) Friction side bearings may not be run in...

  12. 49 CFR 229.69 - Side bearings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....69 Side bearings. (a) Friction side bearings with springs designed to carry weight may not have more than 25 percent of the springs in any one nest broken. (b) Friction side bearings may not be run in...

  13. 49 CFR 229.69 - Side bearings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....69 Side bearings. (a) Friction side bearings with springs designed to carry weight may not have more than 25 percent of the springs in any one nest broken. (b) Friction side bearings may not be run in...

  14. Hybrid Hydrostatic/Transient Roller Bearing Assembly

    NASA Technical Reports Server (NTRS)

    Justak, John F.

    1992-01-01

    Proposed bearing assembly for shaft of high-speed turbopump includes both hydrostatic and rolling-element bearings. Rolling-element bearing unloaded at high speed by centrifugal expansion of outer race and transient retainer.

  15. Random bearings and their stability.

    PubMed

    Mahmoodi Baram, Reza; Herrmann, Hans J

    2005-11-25

    Self-similar space-filling bearings have been proposed some time ago as models for the motion of tectonic plates and appearance of seismic gaps. These models have two features which, however, seem unrealistic, namely, high symmetry in the arrangement of the particles, and lack of a lower cutoff in the size of the particles. In this work, an algorithm for generating random bearings in both two and three dimensions is presented. Introducing a lower cutoff for the sizes of the particles, the instabilities of the bearing under an external force such as gravity, are studied.

  16. Non-contacting "snubber bearing" for passive magnetic bearing systems

    DOEpatents

    Post, Richard F

    2017-08-22

    A new non-contacting magnetic "snubber" bearing is provided for application to rotating systems such as vehicular electromechanical battery systems subject to frequent accelerations. The design is such that in the equilibrium position the drag force of the snubber is very small (milliwatts). However in a typical case, if the rotor is displaced by as little as 2 millimeters a large restoring force is generated without any physical contact between the stationary and rotating parts of the snubber bearing.

  17. Bears, Big and Little. Young Discovery Library Series.

    ERIC Educational Resources Information Center

    Pfeffer, Pierre

    This book is written for children 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume describes: (1) the eight species of bears, including black bear, brown bear, grizzly bear, spectacled bear, sun bear, sloth bear, polar bear, and giant panda; (2) geographical habitats of bears; (3)…

  18. Bears, Big and Little. Young Discovery Library Series.

    ERIC Educational Resources Information Center

    Pfeffer, Pierre

    This book is written for children 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume describes: (1) the eight species of bears, including black bear, brown bear, grizzly bear, spectacled bear, sun bear, sloth bear, polar bear, and giant panda; (2) geographical habitats of bears; (3)…

  19. APPLICATION II: Magnetic Bearing and Flywheel

    NASA Astrophysics Data System (ADS)

    Takaichi, Hiroshi

    The following sections are included: * Introduction * Superconducting magnetic bearing * Large bulk superconductor * Design * Centering device * Bearing performance * Flywheel system using bulk superconductors * Summary and prospects * References

  20. A Passive Magnetic Bearing Flywheel

    NASA Technical Reports Server (NTRS)

    Siebert, Mark; Ebihara, Ben; Jansen, Ralph; Fusaro, Robert L.; Morales, Wilfredo; Kascak, Albert; Kenny, Andrew

    2002-01-01

    A 100 percent passive magnetic bearing flywheel rig employing no active control components was designed, constructed, and tested. The suspension clothe rotor was provided by two sets of radial permanent magnetic bearings operating in the repulsive mode. The axial support was provided by jewel bearings on both ends of the rotor. The rig was successfully operated to speeds of 5500 rpm, which is 65 percent above the first critical speed of 3336 rpm. Operation was not continued beyond this point because of the excessive noise generated by the air impeller and because of inadequate containment in case of failure. Radial and axial stiffnesses of the permanent magnetic bearings were experimentally measured and then compared to finite element results. The natural damping of the rotor was measured and a damping coefficient was calculated.

  1. Gas bearing operates in vacuum

    NASA Technical Reports Server (NTRS)

    Perkins, G. S.

    1975-01-01

    Bearing has restrictions to reduce air leaks and is connected to external pumpout facility which removes exhausted air. Token amount of air which is lost to vacuum is easily removed by conventional vacuum pump.

  2. Mixed-mu superconducting bearings

    DOEpatents

    Hull, J.R.; Mulcahy, T.M.

    1998-03-03

    A mixed-mu superconducting bearing is disclosed including a ferrite structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet structure. The ferrite structure is levitated by said stationary permanent magnet structure. 9 figs.

  3. High-temperature bearing lubricants

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.; Parker, R. J.; Zaretsky, E. V.

    1968-01-01

    Synthetic paraffinic oil lubricates ball bearings at temperatures in the 600 degrees F range. The lubricant contains antiwear and antifoam additives, is thermally stable in the high temperature range, but requires protection from oxygen.

  4. Optimizing journal bearing bit performance

    SciTech Connect

    Moerbe, O.E.; Evans, W.

    1986-10-01

    This article explains that continuous progress in the field of rock bit technology has produced many new designs and improved features in the tri-cone rock bits used today. Much of the research and advancements have centered around journal bearing systems, seals and lubricants leading to greatly extended bearing life. These improved bearing systems, incorporated into both tooth and insert-type bits, have not only increased the effective life of a rock bit, but have also allowed greater energy levels to be applied. This, in turn, has allowed for higher rates of penetration and lower costs per foot of hole drilled. Continuous improvements in journal bearing bits allowing them to run longer and harder have required similar advancements to be made in cutting structures. In tooth bit designs, these improvements have been basically limited to the areas of gauge protection and to application of hardfacing materials.

  5. Making Connections with Teddy Bears.

    ERIC Educational Resources Information Center

    Beougher, Cecile

    1994-01-01

    Presents a hands-on approach to developing connections between mathematics and other subject areas by using thematic webbing. Includes a sample brainstorming aid plus a sample web and thematic unit on teddy bears. (Contains 36 references.) (MKR)

  6. Flex bearing UUEC, volume 2

    NASA Technical Reports Server (NTRS)

    Clapper, M. L.

    1993-01-01

    This volume, Volume 2, of this Flex Bearing UUEC Final Report documents findings and data pertaining to Team B's tasks. Team B was organized as one of two sub-teams of the Unplanned/Unintended Event or Condition (UUEC) board established per InterOffice Memorandum (IOM) A100-FY93-072. Team A determined the cause of the unacceptable unbonds (referred to as 'heat-affect' unbonds), including the initial, light rust film, in the FSM #3 flex bearing was overheating of the Forward End Ring (FER) during cure, specifically in zone 8 of the mold. Team A's findings are documented in Volume 1 of this report. Team B developed flight rationale for existing bearings, based on absence or presence of an unpropitious unbond condition like that in FSM #3's flex bearing.

  7. Mixed-mu superconducting bearings

    DOEpatents

    Hull, John R.; Mulcahy, Thomas M.

    1998-01-01

    A mixed-mu superconducting bearing including a ferrite structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet structure. The ferrite structure is levitated by said stationary permanent magnet structure.

  8. ATM CMG bearing failure analysis

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The cause or causes for the failure of ATM CMG S/N 5 (Skylab 1) and the anomalies associated with ATM CMG S/N 6 (Skylab 2) were investigated. Skylab telemetry data were reviewed and presented in the form of parameter distributions. The theory that the problems were caused by marginal bearing lubrication was studied along with the effects of orbital conditions on lubricants. Bearing tests were performed to investigate the effect of lubricant or lack of lubricant in the ATM CMG bearings and the dispersion and migration of the lubricant. The vacuum and weightless conditions of space were simulated in the bearing tests. Analysis of the results of the tests conducted points to inadequate lubrication as the predominant factor causing the failure of ATM CMG S/N 5 (Skylab 1) and the anomalies associated with ATM CMG S/N 6 (Skylab 2).

  9. Myrmecophagy by Yellowstone grizzly bears

    USGS Publications Warehouse

    Mattson, D.J.

    2001-01-01

    I used data collected during a study of radio-marked grizzly bears (Ursus arctos horribilis) in the Yellowstone region from 1977 to 1992 to investigate myrmecophagy by this population. Although generally not an important source of energy for the bears (averaging 8 mm long) nested in logs over small ants (6 mm long) nested under stones. Optimal conditions for consumption of ants occurred on the warmest sites with ample substrate suitable for ant nests. For ants in mounds, this occurred at low elevations at non-forested sites. For ants in logs, this occurred at low elevations or on southerly aspects where there was abundant, large-diameter, well-decomposed woody debris under an open forest canopy. Grizzly bears selected moderately decomposed logs 4a??5 dm in diameter at midpoint. Ants will likely become a more important food for Yellowstone's grizzly bears as currently important foods decline, owing to disease and warming of the regional climate.

  10. Reflux and Lung Disease

    MedlinePlus

    ... Healthy Eating Reflux and Lung Disease Reflux and Lung Disease Make an Appointment Ask a Question Find a Doctor Many people with chronic lung disease also suffer from gastroesophageal reflux (GERD). In this ...

  11. Interstitial Lung Disease

    MedlinePlus

    ... Conditions Interstitial Lung Disease (ILD)/Pulmonary Fibrosis Interstitial Lung Disease (ILD)/Pulmonary Fibrosis Make an Appointment Refer ... ILD clinical trials and most effective therapies. Interstitial Lung Disease Care at National Jewish Health At National ...

  12. Polyurethane retainers for ball bearings

    NASA Technical Reports Server (NTRS)

    Christy, R. I.

    1973-01-01

    Evaluation of a new ball bearing retainer material is reported. A special composite polyurethane foam ball retainer has been developed that has virtually zero wear, is chemically inert to hydrocarbon lubricants, and stores up to 60 times as much lubricant per unit volume as the most commonly used retainer material, cotton phenolic. This new retainer concept shows promise of years of ball bearing operation without reoiling, based on life testing in high vacuum.

  13. Teddy bear in the heart.

    PubMed

    Krishnamoorthy, K Mahadevan; Krishnamanohar, S Rema

    2004-08-01

    In a patient with native aortic valve endocarditis, transoesphageal echocardiography yielded a teddy bear appearance which is not reported so far. A perivalvular abscess (right ear), the superior vena cava in cross section (left ear) and the dilated (post-stenotic) aortic root (face) made up the teddy bear. This was not a cuddlesome toy but an ominous sign. The genesis of perivalvular abscess as well as the role of transoesphageal echocardiography in its diagnosis and treatment are briefly reviewed.

  14. Lateral dampers for thrust bearings

    NASA Technical Reports Server (NTRS)

    Hibner, D. H.; Szafir, D. R.

    1985-01-01

    The development of lateral damping schemes for thrust bearings was examined, ranking their applicability to various engine classes, selecting the best concept for each engine class and performing an in-depth evaluation. Five major engine classes were considered: large transport, military, small general aviation, turboshaft, and non-manrated. Damper concepts developed for evaluation were: curved beam, constrained and unconstrained elastomer, hybrid boost bearing, hydraulic thrust piston, conical squeeze film, and rolling element thrust face.

  15. Simplified installation of thrust bearings

    NASA Technical Reports Server (NTRS)

    Sensenbaugh, N. D.

    1980-01-01

    Special handling sleeve, key to method of installing thrust bearings, was developed for assembling bearings on shaft of low-pressure oxygen turbo-pump. Method eliminates cooling and vacuum-drying steps which saves time, while also eliminating possibility of corrosion formation. Procedure saves energy because it requires no liquid nitrogen for cooling shaft and no natural gas or electric power for operating vacuum oven.

  16. Improved Superconducting Magnetic Rotary Bearings

    NASA Technical Reports Server (NTRS)

    Flom, Yury; Royston, James

    1992-01-01

    Improved magnetic rotary bearings designed by exploiting properties of type-II superconducting materials. Depending on design and application, bearing provides fixed or adjustable compensation for lateral vector component of weight or other lateral load on rotor. Allows applied magnetic field to penetrate partially in clusters of field lines, with concomitant establishment of undamped circulating electrical currents within material. Type-II superconductors have critical magnetic fields and critical temperatures greater than type-I superconductors.

  17. Predicting Temperatures In Ball Bearings

    NASA Technical Reports Server (NTRS)

    Wagner, William R.; Hemmings, Brad R.

    1988-01-01

    Computer simulations speed design studies. Analyses performed in two or three dimensions. Sizes and shapes of components approximated by zones or nodes connected by gridlines. From geometric information about grids and boundary conditions, properties of bearing and lubricant materials, and information supplied by users, thermal-analysis programs generate mathematical models for thermal transport. Thermal analysis of high-speed rolling contact bearings matured so much that computerized numerical simulations replace expensive time consuming full scale experiments.

  18. SSME Long-life Bearings

    NASA Technical Reports Server (NTRS)

    Butner, M. F.; Murphy, B. T.

    1986-01-01

    Hybrid hydrostatic/ball bearings for LH2 and LO2 service in turbopumps were studied as a means of improving speed and life capabilities. Four hybrid bearing configurations were designed with emphasis on achieving maximum stiffness and damping. Parallel load bearings were tested at steady-state and transient conditions with LH2 (externally fed) and LN2 (internally fed). The hydrostatic elements were tested with Freon 113 for empirical determination of dynamic characteristics. Tests using an eccentric journal for loading showed the externally and internally fed hydrostatic bearings to have significant separated coefficients of direct stiffness and damping. For the internally fed bearing, the strongly speed-dependent cross-coupling stiffness arising from fluid swirl, along with significant cross-coupling damping, resulted in low net effective stiffness and damping. The test method used can produce separated coefficients with a sufficiently elliptic journal orbit; otherwise, only net effective coefficients combining direct and cross-coupling terms can be determined. Testing with nonsynchronous excitation is recommended to avoid this restriction. Investigation of hard materials, including ceramics, is recommended as a means of eliminating the need for the rolling bearing for startup and shutdown support. The testing was performed in 1984 (LH2), 1985 (LN2) and 1985-86 (Freon).

  19. Pharmacological inhibition of caspase-8 limits lung tumour outgrowth

    PubMed Central

    Terlizzi, Michela; Di Crescenzo, Vincenzo Giuseppe; Perillo, Giuseppe; Galderisi, Antonio; Pinto, Aldo; Sorrentino, Rosalinda

    2015-01-01

    Background and Purpose Lung cancer is one of the leading causes of cancer death worldwide. Despite advances in therapy, conventional therapy is still the main treatment and has a high risk of chemotherapy resistance. Caspase-8 is involved in cell death and is a recognized marker for poor patient prognosis. Experimental Approach To elucidate the role of caspase-8 in lung carcinoma, we used human samples of non-small cell lung cancer (NSCLC) and a mouse model of carcinogen-induced lung cancer. Key Results Healthy and cancerous NSCLC samples had similar levels of the active form of caspase-8. Similarly, lung tumour-bearing mice had high levels of the active form of caspase-8. Pharmacological inhibition of caspase-8 by z-IETD-FMK robustly reduced tumour outgrowth and this was closely associated with a reduction in the release of pro-inflammatory cytokines, IL-6, TNF-α, IL-18, IL-1α, IL-33, but not IL-1β. Furthermore, inhibition of caspase-8 reduced the recruitment of innate suppressive cells, such as myeloid-derived suppressor cells, but not of regulatory T cells to lungs of tumour-bearing mice. However, despite the well-known role of caspase-8 in cell death, the apoptotic cascade (caspase-3, caspase-9 and Bcl-2 dependent) was not active in lungs of z-IETD-treated tumour-bearing mice, but instead higher levels of the short segment of c-FLIP (c-FLIPs) were detected. Similarly, human healthy lung samples had higher levels of c-FLIPs than cancerous samples. Conclusions and Implications Our data suggest that caspase-8 is an important orchestrator of cancer-associated inflammation and the presence of short segment of c-FLIP determines whether caspase-8 induces tumour proliferation or tumour arrest/regression in the lung. PMID:25917370

  20. Testing and Lubrication for Single Race Bearings

    SciTech Connect

    Steinhoff, R.G.

    1998-03-04

    Three ES and H-compatible lubricants (Environment, Safety and Health) for single race bearing applications and one hybrid-material single race bearings were evaluated and compared against single race bearings with trichlorotrifluoroethane (Freon) deposition of low molecular weight polytetrafluoroethylene (PTFE) bearing lubricant extracted from Vydax{trademark}. Vydax is a product manufactured by DuPont consisting of various molecular weights of PTFE suspended in trichlorotrifluoroethane (Freon), which is an ozone-depleting solvent. Vydax has been used as a bearing lubricant in stronglink mechanisms since 1974. Hybrid bearings with silicon nitride balls and molded glass-nylon-Teflon retainers, bearings lubricated with titanium carbide (TiC) on the balls, bearings lubricated with sputtered MoS{sub 2} on races and retainers, and bearings lubricated with electrophoretically deposited MoS{sub 2} were evaluated. The bearings were maintained in a preloaded state in bearing cartridges during cycling and vibration tests. Bearings with electrophoretically deposited MoS{sub 2} performed as well as bearings lubricated with Vydax and were the best performing candidate. All candidates were suitable for low preload applications. Bearings with TiC coated balls and bearings lubricated with sputtered MoS{sub 2} on the races and retainers performed well at high preloads, though not as well as bearings lubricated with electrophoretic deposition of MoS{sub 2}. Bearings with silicon nitride balls were not suitable for high preload applications.

  1. Lung tissue mechanics as an emergent phenomenon.

    PubMed

    Suki, Béla; Bates, Jason H T

    2011-04-01

    The mechanical properties of lung parenchymal tissue are both elastic and dissipative, as well as being highly nonlinear. These properties cannot be fully understood, however, in terms of the individual constituents of the tissue. Rather, the mechanical behavior of lung tissue emerges as a macroscopic phenomenon from the interactions of its microscopic components in a way that is neither intuitive nor easily understood. In this review, we first consider the quasi-static mechanical behavior of lung tissue and discuss computational models that show how smooth nonlinear stress-strain behavior can arise through a percolation-like process in which the sequential recruitment of collagen fibers with increasing strain causes them to progressively take over the load-bearing role from elastin. We also show how the concept of percolation can be used to link the pathologic progression of parenchymal disease at the micro scale to physiological symptoms at the macro scale. We then examine the dynamic mechanical behavior of lung tissue, which invokes the notion of tissue resistance. Although usually modeled phenomenologically in terms of collections of springs and dashpots, lung tissue viscoelasticity again can be seen to reflect various types of complex dynamic interactions at the molecular level. Finally, we discuss the inevitability of why lung tissue mechanics need to be complex.

  2. 77 FR 70423 - Black Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-26

    ... Energy Regulatory Commission Black Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC; Notice of Application for Partial Transfer of Licenses, and Soliciting Comments and Motions To Intervene On October 25, 2012, Black Bear Hydro Partners, LLC, sole licensee (transferor) and...

  3. Radiation Therapy for Lung Cancer

    MedlinePlus

    ... are available to help. HELPFUL WEB SITES ON LUNG CANCER American Lung Association www.lung.org Lungcancer.org www.lungcancer.org Lung Cancer Alliance www.lungcanceralliance.org Lung Cancer Online www. ...

  4. Risks of Lung Cancer Screening

    MedlinePlus

    ... Treatment Lung Cancer Prevention Lung Cancer Screening Research Lung Cancer Screening (PDQ®)–Patient Version What is screening? ... These are called diagnostic tests . General Information About Lung Cancer Key Points Lung cancer is a disease ...

  5. Measuring the lung function in the mouse: the challenge of size

    PubMed Central

    Irvin, Charles G; Bates, Jason HT

    2003-01-01

    Measurement of the effects of drugs, mediators and infectious agents on various models of lung disease, as well as assessment of lung function in the intact mouse has the potential for significantly advancing our knowledge of lung disease. However, the small size of the mouse presents significant challenges for the assessment of lung function. Because of compromises made between precision and noninvasiveness, data obtained may have an uncertain bearing on the mechanical response of the lung. Nevertheless, considerable recent progress has been made in developing valid and useful measures of mouse lung function. These advances, resulting in our current ability to measure sophisticated indices of lung function in laboratory animals, are likely to lead to important insights into the mechanisms of lung disease. PMID:12783622

  6. 36 CFR 13.1236 - Bear orientation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Bear orientation. 13.1236... Developed Area § 13.1236 Bear orientation. All persons visiting the BCDA must receive an NPS-approved Bear Orientation. Failure to receive an NPS-approved Bear Orientation is prohibited. ...

  7. 49 CFR 229.69 - Side bearings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Side bearings. 229.69 Section 229.69....69 Side bearings. (a) Friction side bearings with springs designed to carry weight may not have more than 25 percent of the springs in any one nest broken. (b) Friction side bearings may not be run in...

  8. Journal gas bearing for curved surfaces

    NASA Technical Reports Server (NTRS)

    Redmon, J. W.

    1969-01-01

    Optimizing bearing length and permissible axis curvature alleviates distortion of film gap of gas lubricated journal bearing in deployment mechanisms. Required bearing length is divided into two shorter bearings interconnected by links which allow satisfactory conformity with the bent, load-carrying member.

  9. 36 CFR 13.1236 - Bear orientation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Bear orientation. 13.1236... Developed Area § 13.1236 Bear orientation. All persons visiting the BCDA must receive an NPS-approved Bear Orientation. Failure to receive an NPS-approved Bear Orientation is prohibited....

  10. 36 CFR 13.1236 - Bear orientation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Bear orientation. 13.1236... Developed Area § 13.1236 Bear orientation. All persons visiting the BCDA must receive an NPS-approved Bear Orientation. Failure to receive an NPS-approved Bear Orientation is prohibited....

  11. 36 CFR 13.1236 - Bear orientation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Bear orientation. 13.1236... Developed Area § 13.1236 Bear orientation. All persons visiting the BCDA must receive an NPS-approved Bear Orientation. Failure to receive an NPS-approved Bear Orientation is prohibited....

  12. 36 CFR 13.1236 - Bear orientation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Bear orientation. 13.1236... Developed Area § 13.1236 Bear orientation. All persons visiting the BCDA must receive an NPS-approved Bear Orientation. Failure to receive an NPS-approved Bear Orientation is prohibited....

  13. Cryogenic Magnetic Bearing Test Facility (CMBTF)

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Cryogenic Magnetic Bearing Test Facility (CMBTF) was designed and built to evaluate compact, lightweight magnetic bearings for use in the SSME's (space shuttle main engine) liquid oxygen and liquid hydrogen turbopumps. State of the art and tradeoff studies were conducted which indicated that a hybrid permanent magnet bias homopolar magnetic bearing design would be smaller, lighter, and much more efficient than conventional industrial bearings. A test bearing of this type was designed for the test rig for use at both room temperature and cryogenic temperature (-320 F). The bearing was fabricated from state-of-the-art materials and incorporated into the CMBTF. Testing at room temperature was accomplished at Avcon's facility. These preliminary tests indicated that this magnetic bearing is a feasible alternative to older bearing technologies. Analyses showed that the hybrid magnetic bearing is one-third the weight, considerably smaller, and uses less power than previous generations of magnetic bearings.

  14. Lung surfactant.

    PubMed Central

    Rooney, S A

    1984-01-01

    Aspects of pulmonary surfactant are reviewed from a biochemical perspective. The major emphasis is on the lipid components of surfactant. Topics reviewed include surfactant composition, cellular and subcellular sites as well as pathways of biosynthesis of phosphatidylcholine, disaturated phosphatidylcholine and phosphatidylglycerol. The surfactant system in the developing fetus and neonate is considered in terms of phospholipid content and composition, rates of precursor incorporation, activities of individual enzymes of phospholipid synthesis and glycogen content and metabolism. The influence of the following hormones and other factors on lung maturation and surfactant production is discussed: glucocorticoids, thyroid hormone, estrogen, prolactin, cyclic AMP, beta-adrenergic and cholinergic agonists, prostaglandins and growth factors. The influence of maternal diabetes, fetal sex, stress and labor are also considered. Nonphysiologic and toxic agents which influence surfactant in the fetus, newborn and adult are reviewed. PMID:6145585

  15. Superconductor bearings, flywheels and transportation

    NASA Astrophysics Data System (ADS)

    Werfel, F. N.; Floegel-Delor, U.; Rothfeld, R.; Riedel, T.; Goebel, B.; Wippich, D.; Schirrmeister, P.

    2012-01-01

    This paper describes the present status of high temperature superconductors (HTS) and of bulk superconducting magnet devices, their use in bearings, in flywheel energy storage systems (FESS) and linear transport magnetic levitation (Maglev) systems. We report and review the concepts of multi-seeded REBCO bulk superconductor fabrication. The multi-grain bulks increase the averaged trapped magnetic flux density up to 40% compared to single-grain assembly in large-scale applications. HTS magnetic bearings with permanent magnet (PM) excitation were studied and scaled up to maximum forces of 10 kN axially and 4.5 kN radially. We examine the technology of the high-gradient magnetic bearing concept and verify it experimentally. A large HTS bearing is tested for stabilizing a 600 kg rotor of a 5 kWh/250 kW flywheel system. The flywheel rotor tests show the requirement for additional damping. Our compact flywheel system is compared with similar HTS-FESS projects. A small-scale compact YBCO bearing with in situ Stirling cryocooler is constructed and investigated for mobile applications. Next we show a successfully developed modular linear Maglev system for magnetic train operation. Each module levitates 0.25t at 10 mm distance during one-day operation without refilling LN2. More than 30 vacuum cryostats containing multi-seeded YBCO blocks are fabricated and are tested now in Germany, China and Brazil.

  16. Hydrostatic bearings for a turbine fluid flow metering device

    DOEpatents

    Fincke, James R.

    1982-01-01

    A rotor assembly fluid metering device has been improved by development of a hydrostatic bearing fluid system which provides bearing fluid at a common pressure to rotor assembly bearing surfaces. The bearing fluid distribution system produces a uniform film of fluid between bearing surfaces and allows rapid replacement of bearing fluid between bearing surfaces, thereby minimizing bearing wear and corrosion.

  17. Hydrostatic bearings for a turbine fluid flow metering device

    DOEpatents

    Fincke, J.R.

    1982-05-04

    A rotor assembly fluid metering device has been improved by development of a hydrostatic bearing fluid system which provides bearing fluid at a common pressure to rotor assembly bearing surfaces. The bearing fluid distribution system produces a uniform film of fluid between bearing surfaces and allows rapid replacement of bearing fluid between bearing surfaces, thereby minimizing bearing wear and corrosion. 3 figs.

  18. Interstitial Lung Diseases

    MedlinePlus

    Interstitial lung disease is the name for a large group of diseases that inflame or scar the lungs. The inflammation and scarring make it hard to ... air is responsible for some types of interstitial lung diseases. Specific types include Black lung disease among ...

  19. 'Dodo' and 'Baby Bear' Trenches

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA's Phoenix Mars Lander's Surface Stereo Imager took this image on Sol 11 (June 5, 2008), the eleventh day after landing. It shows the trenches dug by Phoenix's Robotic Arm. The trench on the left is informally called 'Dodo' and was dug as a test. The trench on the right is informally called 'Baby Bear.' The sample dug from Baby Bear will be delivered to the Phoenix's Thermal and Evolved-Gas Analyzer, or TEGA. The Baby Bear trench is 9 centimeters (3.1 inches) wide and 4 centimeters (1.6 inches) deep.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  20. Magnetic bearings with zero bias

    NASA Technical Reports Server (NTRS)

    Brown, Gerald V.; Grodsinsky, Carlos M.

    1991-01-01

    A magnetic bearing operating without a bias field has supported a shaft rotating at speeds up to 12,000 rpm with the usual four power supplies and with only two. A magnetic bearing is commonly operated with a bias current equal to half of the maximum current allowable in its coils. This linearizes the relation between net force and control current and improves the force slewing rate and hence the band width. The steady bias current dissipates power, even when no force is required from the bearing. The power wasted is equal to two-thirds of the power at maximum force output. Examined here is the zero bias idea. The advantages and disadvantages are noted.

  1. 'Dodo' and 'Baby Bear' Trenches

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA's Phoenix Mars Lander's Surface Stereo Imager took this image on Sol 11 (June 5, 2008), the eleventh day after landing. It shows the trenches dug by Phoenix's Robotic Arm. The trench on the left is informally called 'Dodo' and was dug as a test. The trench on the right is informally called 'Baby Bear.' The sample dug from Baby Bear will be delivered to the Phoenix's Thermal and Evolved-Gas Analyzer, or TEGA. The Baby Bear trench is 9 centimeters (3.1 inches) wide and 4 centimeters (1.6 inches) deep.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  2. Ex vivo lung perfusion.

    PubMed

    Reeb, Jeremie; Cypel, Marcelo

    2016-03-01

    Lung transplantation is an established life-saving therapy for patients with end-stage lung disease. Unfortunately, greater success in lung transplantation is hindered by a shortage of lung donors and the relatively poor early-, mid-, and long-term outcomes associated with severe primary graft dysfunction. Ex vivo lung perfusion has emerged as a modern preservation technique that allows for a more accurate lung assessment and improvement in lung quality. This review outlines the: (i) rationale behind the method; (ii) techniques and protocols; (iii) Toronto ex vivo lung perfusion method; (iv) devices available; and (v) clinical experience worldwide. We also highlight the potential of ex vivo lung perfusion in leading a new era of lung preservation.

  3. Air bearing vacuum seal assembly

    DOEpatents

    Booth, Rex

    1978-01-01

    An air bearing vacuum seal assembly capable of rotating at the speed of several thousand revolutions per minute using an air cushion to prevent the rotating and stationary parts from touching, and a two stage differential pumping arrangement to maintain the pressure gradient between the air cushion and the vacuum so that the leak rate into the vacuum is, for example, less than 1 .times. 10.sup.-4 Pa m.sup.3 /s. The air bearing vacuum seal has particular application for mounting rotating targets to an evacuated accelerator beam tube for bombardment of the targets with high-power charged particle beams in vacuum.

  4. Solid Lubricated Rolling Element Bearings

    DTIC Science & Technology

    1980-02-15

    gyro bearing balls (as received), at various SEM magnifications 16 • VVi 7. TMI TiC/ MoS2 sputtered 52100 gyro bearing inner and outer race...outer race ball path (MoS^ removed with Oakite 126 HD), at 800X SEM magnification and EDX scrutiny 21 12. TMI TiC/ MoS2 sputtered 52100...target (Reference 4) 23 14. Overall top view of a 5-station, 15 gyro component, planetary rotating sputtering fixture of TMI for TiC/ U ^-■ MoS2

  5. Isolation of epithelial, endothelial, and immune cells from lungs of transgenic mice with oncogene-induced lung adenocarcinomas.

    PubMed

    Bantikassegn, Amlak; Song, Xiaoling; Politi, Katerina

    2015-04-01

    Genetically engineered mouse models of lung adenocarcinoma have proven invaluable for understanding mechanisms of tumorigenesis, therapy response, and drug resistance. However, mechanistic studies focused on studying these processes in tumor-bearing mouse lungs are confounded by the fact that, in most cases, relevant signaling pathways are analyzed in whole-lung preparations, which are composed of a heterogeneous mixture of cells. Given our increasing knowledge about the roles played by different subpopulations of cells in the development of lung adenocarcinoma, separating the major cellular compartments of the tumor microenvironment is recommended to allow for a precise analysis of relevant pathways in each isolated cell type. In this study, we optimized magnetic- and fluorescence-based isolation protocols to segregate lung epithelial (CD326/epithelial cell adhesion molecule-positive), endothelial (CD31-positive), and immune (CD45-positive) cells, with high purity, from the lungs of transgenic mice with mutant epidermal growth factor receptor-induced lung adenocarcinomas. This approach, which can potentially be extended to additional lung adenocarcinoma models, enables delineation of the molecular features of individual cell types that can be used to gain insight into their roles in lung adenocarcinoma initiation, progression, and response to therapy.

  6. Wave Journal Bearing. Part 1: Analysis

    NASA Technical Reports Server (NTRS)

    Dimofte, Florin

    1995-01-01

    A wave journal bearing concept features a waved inner bearing diameter of the non-rotating bearing side and it is an alternative to the plain journal bearing. The wave journal bearing has a significantly increased load capacity in comparison to the plain journal bearing operating at the same eccentricity. It also offers greater stability than the plain circular bearing under all operating conditions. The wave bearing's design is relatively simple and allows the shaft to rotate in either direction. Three wave bearings are sensitive to the direction of an applied stationary side load. Increasing the number of waves reduces the wave bearing's sensitivity to the direction of the applied load relative to the wave. However, the range in which the bearing performance can be varied decreases as the number of waves increases. Therefore, both the number and the amplitude of the waves must be properly selected to optimize the wave bearing design for a specific application. It is concluded that the stiffness of an air journal bearing, due to hydrodynamic effect, could be doubled and made to run stably by using a six or eight wave geometry with a wave amplitude approximately half of the bearing radial clearance.

  7. Extracellular matrix mechanics in lung parenchymal diseases.

    PubMed

    Suki, Béla; Bates, Jason H T

    2008-11-30

    In this review, we examine how the extracellular matrix (ECM) of the lung contributes to the overall mechanical properties of the parenchyma, and how these properties change in disease. The connective tissues of the lung are composed of cells and ECM, which includes a variety of biological macromolecules and water. The macromolecules that are most important in determining the mechanical properties of the ECM are collagen, elastin, and proteoglycans. We first discuss the various components of the ECM and how their architectural organization gives rise to the mechanical properties of the parenchyma. Next, we examine how mechanical forces can affect the physiological functioning of the lung parenchyma. Collagen plays an especially important role in determining the homeostasis and cellular responses to injury because it is the most important load-bearing component of the parenchyma. We then demonstrate how the concept of percolation can be used to link microscopic pathologic alterations in the parenchyma to clinically measurable lung function during the progression of emphysema and fibrosis. Finally, we speculate about the possibility of using targeted tissue engineering to optimize treatment of these two major lung diseases.

  8. High performance rolling element bearing

    NASA Technical Reports Server (NTRS)

    Bursey, Jr., Roger W. (Inventor); Olinger, Jr., John B. (Inventor); Owen, Samuel S. (Inventor); Poole, William E. (Inventor); Haluck, David A. (Inventor)

    1993-01-01

    A high performance rolling element bearing (5) which is particularly suitable for use in a cryogenically cooled environment, comprises a composite cage (45) formed from glass fibers disposed in a solid lubricant matrix of a fluorocarbon polymer. The cage includes inserts (50) formed from a mixture of a soft metal and a solid lubricant such as a fluorocarbon polymer.

  9. Gradient Tempering Of Bearing Races

    NASA Technical Reports Server (NTRS)

    Parr, Richardson A.

    1991-01-01

    Gradient-tempering process increases fracture toughness and resistance to stress-corrosion cracking of ball-bearing races made of hard, strong steels and subject to high installation stresses and operation in corrosive media. Also used in other applications in which local toughening of high-strength/low-toughness materials required.

  10. Polar bear research in Alaska

    USGS Publications Warehouse

    Durner, George M.; Amstrup, Steven C.; York, Geoff S.; Regehr, Eric V.; Simac, Kristin; Smith, Tom S.; Partridge, Steven T.; Bentzen, Torsten; Amstrup, Kristin S.; Douglas, David C.; Aars, Jon; Lunn, Nicholas J.; Derocher, Andrew E.; Aars, Jon; Lunn, Nicholas J.; Derocher, Andrew E.

    2006-01-01

    Since the 13th Working Meeting of the Polar Bear Specialist Group the U.S. Geological Survey (USGS) has seen the completion of many research projects and the start of many new ones. Much has been accomplished and yet we have new challenges awaiting us. This report summarises our focal questions and progress in those areas.

  11. Little Bear Fire Summary Report

    Treesearch

    Sarah McCaffrey; Melanie Stidham; Hannah. Brenkert-Smith

    2013-01-01

    In June 2012, immediately after the Little Bear Fire burned outside Ruidoso, New Mexico, a team of researchers interviewed fire managers, local personnel, and residents to understand perceptions of the event itself, communication, evacuation, and pre-fire preparedness. The intensity of fire behavior and resulting loss of 242 homes made this a complex fire with a...

  12. Beth Starts Like Brown Bear!

    ERIC Educational Resources Information Center

    Fawcett, Gay

    1994-01-01

    Recounts a reading teacher's illuminating experience with a first grader who enjoyed reading Bill Martin's "Brown Bear" books, despite being labeled as dyslexic. Dyslexia is an elusive condition that is biological in origin and distinct from other reading problems. New research shows that reading difficulties, including dyslexia, occur as part of…

  13. Intelligent Engine Systems: Bearing System

    NASA Technical Reports Server (NTRS)

    Singh, Arnant P.

    2008-01-01

    The overall requirements necessary for sensing bearing distress and the related criteria to select a particular rotating sensor were established during the phase I. The current phase II efforts performed studies to evaluate the Robustness and Durability Enhancement of the rotating sensors, and to design, and develop the Built-in Telemetry System concepts for an aircraft engine differential sump. A generic test vehicle that can test the proposed bearing diagnostic system was designed, developed, and built. The Timken Company, who also assisted with testing the GE concept of using rotating sensors for the differential bearing diagnostics during previous phase, was selected as a subcontractor to assist General Electric (GE) for the design, and procurement of the test vehicle. A purchase order was prepared to define the different sub-tasks, and deliverables for this task. The University of Akron was selected to provide the necessary support for installing, and integrating the test vehicle with their newly designed test facility capable of simulating the operating environment for the planned testing. The planned testing with good and damaged bearings will be on hold pending further continuation of this effort during next phase.

  14. We still need Smokey Bear!

    USGS Publications Warehouse

    Keeley, Jon E.

    2001-01-01

    It was gratifying to see articles in recent issues of Fire Management Today clarifying the role of Smokey Bear in wildland fire management strategies (Baily 1999; Brown 1999). These articles clearly spelled out Smokey’s importance in reducing unplanned human-ignited wildland fires and rightly criticized attempts to detract from Smokey’s campaign (Williams 1995; see also Vogl 1973).

  15. Beth Starts Like Brown Bear!

    ERIC Educational Resources Information Center

    Fawcett, Gay

    1994-01-01

    Recounts a reading teacher's illuminating experience with a first grader who enjoyed reading Bill Martin's "Brown Bear" books, despite being labeled as dyslexic. Dyslexia is an elusive condition that is biological in origin and distinct from other reading problems. New research shows that reading difficulties, including dyslexia, occur as part of…

  16. Satellite monitoring of black bear.

    NASA Technical Reports Server (NTRS)

    Craighead, J. J.; Craighead, F. C., Jr.; Varney, J. R.; Cote, C. E.

    1971-01-01

    Description of a feasibility experiment recently performed to test the use of a satellite system for telemetering environmental and physiological data from the winter den of a 'hibernating' black bear, Ursus americanus. The instrumentation procedure and evaluations of the equipment performance and sensory data obtained are discussed in detail.

  17. Satellite monitoring of black bear.

    NASA Technical Reports Server (NTRS)

    Craighead, J. J.; Craighead, F. C., Jr.; Varney, J. R.; Cote, C. E.

    1971-01-01

    Description of a feasibility experiment recently performed to test the use of a satellite system for telemetering environmental and physiological data from the winter den of a 'hibernating' black bear, Ursus americanus. The instrumentation procedure and evaluations of the equipment performance and sensory data obtained are discussed in detail.

  18. Losses of Superconductor Journal Bearing

    NASA Astrophysics Data System (ADS)

    Han, Y. H.; Hull, J. R.; Han, S. C.; Jeong, N. H.; Oh, J. M.; Sung, T. H.

    2004-06-01

    A high-temperature superconductor (HTS) journal bearing was studied for rotational loss. Two HTS bearings support the rotor at top and bottom. The rotor weight is 4 kg and the length is about 300 mm. Both the top and bottom bearings have two permanent magnet (PM) rings with an iron pole piece separating them. Each HTS journal bearing is composed of six pieces of superconductor blocks of size 35×25×10 mm. The HTS blocks are encased in a cryochamber through which liquid nitrogen flows. The inner spool of the cryochamber is made from G-10 to reduce eddy current loss, and the rest of the cryochamber is stainless steel. The magnetic field from the PM rings is < 10 mT on the stainless part. The rotational drag was measured over the same speed range at several chamber pressures. Results indicate that a chamber pressure of 0.4 mtorr is sufficiently low to minimize windage loss, and the 10 mT design criterion for the magnetic field on the stainless part of the cryochamber is too high.

  19. Technology advances for magnetic bearings

    NASA Astrophysics Data System (ADS)

    Nolan, Steve; Hung, John Y.

    1996-03-01

    This paper describes the state-of-the-art in magnetic bearing technology and applications, and some of advances under development through the joint efforts of Rocketdyne Division of Rockwell International and Auburn University. Advances in the areas of nonlinear control systems design, digital controller implementation, and power electronics are discussed.

  20. Himalayan black bear mauling: offense or defense?

    PubMed

    Thakur, Jagdeep Singh; Mohan, Chander; Sharma, Dev R

    2007-01-01

    The Asiatic Black Bear (Ursus thibetanus or Selenarctos thibetanus), also known as the Tibetan black bear, the Himalayan black bear, or the moon bear is a omnivorous mammal. This animal is declared threatened animal and rarely comes in human contact. Recent decrease in forest area has, however, increased the chances of bear-human interaction, hence causing injuries to humans. There is only one published report in English literature on Himalayan black bear mauling. We present 5 cases referred to our department over a period of 1 year.

  1. Active magnetic bearings give systems a lift

    NASA Astrophysics Data System (ADS)

    O'Connor, Leo

    1992-07-01

    While the active magnetic bearings currently being used in such specialized applications as centrifugal compressors for natural gas pumps are more expensive than conventional bearings, they furnish improved machine service life, controlled damping of high-speed rotors to eliminate critical-speed vibrations, and the obviation of lubrication systems. Attention is presently given to magnetic bearings used by the electric power industry, homopolar magnetic radial and thrust bearings, weapon-system and gas turbine engine applications of magnetic bearings, and the benefits of magnetic bearings for energy-storage flywheels.

  2. TOOL ASSEMBLY WITH BI-DIRECTIONAL BEARING

    DOEpatents

    Longhurst, G.E.

    1961-07-11

    A two-direction motion bearing which is incorporated in a refueling nuclear fuel element trsnsfer tool assembly is described. A plurality of bi- directional bearing assembliesare fixed equi-distantly about the circumference of the transfer tool assembly to provide the tool assembly with a bearing surface- for both axial and rotational motion. Each bi-directional bearing assembly contains a plurality of circumferentially bulged rollers mounted in a unique arrangement which will provide a bearing surface for rotational movement of the tool assembly within a bore. The bi-direc tional bearing assembly itself is capable of rational motion and thus provides for longitudinal movement of the tool assembly.

  3. Characteristics of high-stiffness superconducting bearing

    SciTech Connect

    Okano, M.; Tamada, N.; Fuchino, S.; Ishii, I.

    1996-07-01

    Magnetic bearings using a high-Tc superconductor have been studied. Generally the bearing makes use of the pinning effects to get the levitation force. The stiffness of the bearing, however, is extremely low as compared with industrial-scale conventional one. To improve the bearing stiffness the authors propose a disc-type repulsive superconducting thrust bearing with a slit for the restraint of the flux. Both theoretical and experimental evaluation on the load performance was carried out, and it is clarified that the proposed superconducting bearing has higher stiffness.

  4. Epidemiology of Lung Cancer

    PubMed Central

    Brock, Malcolm V.; Ford, Jean G.; Samet, Jonathan M.; Spivack, Simon D.

    2013-01-01

    Background: Ever since a lung cancer epidemic emerged in the mid-1900s, the epidemiology of lung cancer has been intensively investigated to characterize its causes and patterns of occurrence. This report summarizes the key findings of this research. Methods: A detailed literature search provided the basis for a narrative review, identifying and summarizing key reports on population patterns and factors that affect lung cancer risk. Results: Established environmental risk factors for lung cancer include smoking cigarettes and other tobacco products and exposure to secondhand tobacco smoke, occupational lung carcinogens, radiation, and indoor and outdoor air pollution. Cigarette smoking is the predominant cause of lung cancer and the leading worldwide cause of cancer death. Smoking prevalence in developing nations has increased, starting new lung cancer epidemics in these nations. A positive family history and acquired lung disease are examples of host factors that are clinically useful risk indicators. Risk prediction models based on lung cancer risk factors have been developed, but further refinement is needed to provide clinically useful risk stratification. Promising biomarkers of lung cancer risk and early detection have been identified, but none are ready for broad clinical application. Conclusions: Almost all lung cancer deaths are caused by cigarette smoking, underscoring the need for ongoing efforts at tobacco control throughout the world. Further research is needed into the reasons underlying lung cancer disparities, the causes of lung cancer in never smokers, the potential role of HIV in lung carcinogenesis, and the development of biomarkers. PMID:23649439

  5. Journal and Wave Bearing Impedance Calculation Software

    NASA Technical Reports Server (NTRS)

    Hanford, Amanda; Campbell, Robert

    2012-01-01

    The wave bearing software suite is a MALTA application that computes bearing properties for user-specified wave bearing conditions, as well as plain journal bearings. Wave bearings are fluid film journal bearings with multi-lobed wave patterns around the circumference of the bearing surface. In this software suite, the dynamic coefficients are outputted in a way for easy implementation in a finite element model used in rotor dynamics analysis. The software has a graphical user interface (GUI) for inputting bearing geometry parameters, and uses MATLAB s structure interface for ease of interpreting data. This innovation was developed to provide the stiffness and damping components of wave bearing impedances. The computational method for computing bearing coefficients was originally designed for plain journal bearings and tilting pad bearings. Modifications to include a wave bearing profile consisted of changing the film thickness profile given by an equation, and writing an algorithm to locate the integration limits for each fluid region. Careful consideration was needed to implement the correct integration limits while computing the dynamic coefficients, depending on the form of the input/output variables specified in the algorithm.

  6. Hybrid bearings for turbopumps and the like

    NASA Technical Reports Server (NTRS)

    Justak, John F. (Inventor); Owens, Gregg R. (Inventor)

    1994-01-01

    In rocket engines power is usually obtained by burning fuel and oxidizer which are mixed, pressurized, and directed to a combustion chamber by means of turbopumps. Roller bearings are generally used in these turbopumps, but because of bearing demands hydrostatic bearings were proposed. The use of such bearings is quite feasible because during flight hydrostatic lubrication can reduce roller bearing wear. A disadvantage of such proposals is that during startup, acceleration, and shutdown high pressure fluids are not available for hydrostatic bearings. The fluid lubrication film is not always present in bearings of turbopumps. During these periods a second bearing is required to carry the load. This requirement suggests the use of hybrid bearings in rocket engine turbopumps. Such duplex bearings were provided, but when their inner races are keyed to the shaft or journal two of them are required. And such duplex bearings do not wear evenly. A hybrid hydrostatic-rolling element bearing was provided wherein the rolling element bearing is locked on the stationary housing rather than on the rotating journal.

  7. Alaskan brown bears, humans, and habituation

    USGS Publications Warehouse

    Smith, Thomas; Herrero, Stephen; DeBruyn, Terry D.

    2005-01-01

    We present a new paradigm for understanding habituation and the role it plays in brown bear (Ursus arctos) populations and interactions with humans in Alaska. We assert that 3 forms of habituation occur in Alaska: bear-to-bear, bear-to-human, and human-to-bear. We present data that supports our theory that bear density is an important factor influencing a bear’s overt reaction distance (ORD); that as bear density increases, overt reaction distance decreases, as does the likelihood of bear– human interactions. We maintain that the effects of bear-to-bear habituation are largely responsible for not only shaping bear aggregations but also for creating the relatively safe environment for bear viewing experienced at areas where there are high densities of brown bears. By promoting a better understanding of the forces that shape bear social interactions within populations and with humans that mingle with them, we can better manage human activities and minimize bear–human conflict.

  8. Hybrid bearings for turbopumps and the like

    NASA Astrophysics Data System (ADS)

    Justak, John F.; Owens, Gregg R.

    1993-01-01

    In rocket engines power is usually obtained by burning fuel and oxidizer which are mixed, pressurized, and directed to a combustion chamber by means of turbopumps. Roller bearings are generally used in these turbopumps, but because of bearing demands hydrostatic bearings were proposed. The use of such bearings is quite feasible because during flight hydrostatic lubrication can reduce roller bearing wear. A disadvantage of such proposals is that during startup, acceleration, and shutdown high pressure fluids are not available for hydrostatic bearings. The fluid lubrication film is not always present in bearings of turbopumps. During these periods a second bearing is required to carry the load. This requirement suggests the use of hybrid bearings in rocket engine turbopumps. Such duplex bearings were provided, but when their inner races are keyed to the shaft or journal two of them are required. And such duplex bearings do not wear evenly. A hybrid hydrostatic-rolling element bearing was provided wherein the rolling element bearing is locked on the stationary housing rather than on the rotating journal.

  9. Hybrid bearings for turbopumps and the like

    NASA Astrophysics Data System (ADS)

    Justak, John F.; Owens, Gregg R.

    1994-09-01

    In rocket engines power is usually obtained by burning fuel and oxidizer which are mixed, pressurized, and directed to a combustion chamber by means of turbopumps. Roller bearings are generally used in these turbopumps, but because of bearing demands hydrostatic bearings were proposed. The use of such bearings is quite feasible because during flight hydrostatic lubrication can reduce roller bearing wear. A disadvantage of such proposals is that during startup, acceleration, and shutdown high pressure fluids are not available for hydrostatic bearings. The fluid lubrication film is not always present in bearings of turbopumps. During these periods a second bearing is required to carry the load. This requirement suggests the use of hybrid bearings in rocket engine turbopumps. Such duplex bearings were provided, but when their inner races are keyed to the shaft or journal two of them are required. And such duplex bearings do not wear evenly. A hybrid hydrostatic-rolling element bearing was provided wherein the rolling element bearing is locked on the stationary housing rather than on the rotating journal.

  10. Short-bearing approximation for full journal bearings

    NASA Technical Reports Server (NTRS)

    Ocvirk, F W

    1952-01-01

    A short-bearing approximation of pressure distribution in the oil film is presented which is an extension of the pressure-distribution function of Michell and Cardullo and includes end-leakage effects. Equations giving applied load, attitude angle, location and magnitude of peak film pressure, friction, and required oil flow rate as functions of the eccentricity ratio are also given. The capacity number, a basic non dimensional quantity resulting from this analysis is the product of the Sommerfeld number and the square of the length-diameter ratio. Curves determined by this analysis are compared with previously published experimental data and theoretical curves of Sommerfeld and Cameron and Wood. Conclusions reached indicate that this approximation is of practical value for analysis of short bearings.

  11. Mobile bearing and fixed bearing total knee arthroplasty

    PubMed Central

    Dolfin, Marco; Saccia, Francesco

    2016-01-01

    The mobile bearing (MB) concept in total knee arthroplasty (TKA) was developed as an alternative to fixed bearing (FB) implants in order to reduce wear and improve range of motion (ROM), especially focused on younger patients. Unfortunately, its theoretical advantages are still controversial. In this paper we exhibit a review of the more recent literature available comparing FB and MB designs in biomechanical and clinical aspects, including observational studies, clinical trials, national and international registries analyses, randomized controlled trials, meta-analyses and Cochrane reviews. Except for some minor aspects, none of the studies published so far has reported a significant improvement related to MBs regarding patient satisfaction, clinical, functional and radiological outcome or medium and long-term survivorship. Thus the presumed superiority of MBs over FBs appears largely inconsistent. The routine use of MB is not currently supported by adequate evidences; implant choice should be therefore made on the basis of other factors, including cost and surgeon experience. PMID:27162777

  12. Mobile bearing and fixed bearing total knee arthroplasty.

    PubMed

    Capella, Marcello; Dolfin, Marco; Saccia, Francesco

    2016-04-01

    The mobile bearing (MB) concept in total knee arthroplasty (TKA) was developed as an alternative to fixed bearing (FB) implants in order to reduce wear and improve range of motion (ROM), especially focused on younger patients. Unfortunately, its theoretical advantages are still controversial. In this paper we exhibit a review of the more recent literature available comparing FB and MB designs in biomechanical and clinical aspects, including observational studies, clinical trials, national and international registries analyses, randomized controlled trials, meta-analyses and Cochrane reviews. Except for some minor aspects, none of the studies published so far has reported a significant improvement related to MBs regarding patient satisfaction, clinical, functional and radiological outcome or medium and long-term survivorship. Thus the presumed superiority of MBs over FBs appears largely inconsistent. The routine use of MB is not currently supported by adequate evidences; implant choice should be therefore made on the basis of other factors, including cost and surgeon experience.

  13. Functional vascularized lung grafts for lung bioengineering

    PubMed Central

    Dorrello, N. Valerio; Guenthart, Brandon A.; O’Neill, John D.; Kim, Jinho; Cunningham, Katherine; Chen, Ya-Wen; Biscotti, Mauer; Swayne, Theresa; Wobma, Holly M.; Huang, Sarah X. L.; Snoeck, Hans-Willem; Bacchetta, Matthew; Vunjak-Novakovic, Gordana

    2017-01-01

    End-stage lung disease is the third leading cause of death worldwide, accounting for 400,000 deaths per year in the United States alone. To reduce the morbidity and mortality associated with lung disease, new therapeutic strategies aimed at promoting lung repair and increasing the number of donor lungs available for transplantation are being explored. Because of the extreme complexity of this organ, previous attempts at bioengineering functional lungs from fully decellularized or synthetic scaffolds lacking functional vasculature have been largely unsuccessful. An intact vascular network is critical not only for maintaining the blood-gas barrier and allowing for proper graft function but also for supporting the regenerative cells. We therefore developed an airway-specific approach to removing the pulmonary epithelium, while maintaining the viability and function of the vascular endothelium, using a rat model. The resulting vascularized lung grafts supported the attachment and growth of human adult pulmonary cells and stem cell–derived lung-specified epithelial cells. We propose that de-epithelialization of the lung with preservation of intact vasculature could facilitate cell therapy of pulmonary epithelium and enable bioengineering of functional lungs for transplantation. PMID:28875163

  14. High-fat diet enhances and plasminogen activator inhibitor-1 deficiency attenuates bone loss in mice with Lewis Lung carcinoma

    USDA-ARS?s Scientific Manuscript database

    This study determined the effects of a high-fat diet and plasminogen activator inhibitor-1 deficiency (PAI-1-/-) on bone structure in mice bearing Lewis lung carcinoma (LLC) in lungs. Reduction in bone volume fraction (BV/TV) by 22% and 21%, trabecular number (Tb.N) by 8% and 4% and bone mineral de...

  15. A Preliminary Foil Gas Bearing Performance Map

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Radil, Kevin C.; Bruckner, Robert J.; Howard, S. Adam

    2006-01-01

    Recent breakthrough improvements in foil gas bearing load capacity, high temperature tribological coatings and computer based modeling have enabled the development of increasingly larger and more advanced Oil-Free Turbomachinery systems. Successful integration of foil gas bearings into turbomachinery requires a step wise approach that includes conceptual design and feasibility studies, bearing testing, and rotor testing prior to full scale system level demonstrations. Unfortunately, the current level of understanding of foil gas bearings and especially their tribological behavior is often insufficient to avoid developmental problems thereby hampering commercialization of new applications. In this paper, a new approach loosely based upon accepted hydrodynamic theory, is developed which results in a "Foil Gas Bearing Performance Map" to guide the integration process. This performance map, which resembles a Stribeck curve for bearing friction, is useful in describing bearing operating regimes, performance safety margins, the effects of load on performance and limiting factors for foil gas bearings.

  16. Rolling Element Bearing Stiffness Matrix Determination (Presentation)

    SciTech Connect

    Guo, Y.; Parker, R.

    2014-01-01

    Current theoretical bearing models differ in their stiffness estimates because of different model assumptions. In this study, a finite element/contact mechanics model is developed for rolling element bearings with the focus of obtaining accurate bearing stiffness for a wide range of bearing types and parameters. A combined surface integral and finite element method is used to solve for the contact mechanics between the rolling elements and races. This model captures the time-dependent characteristics of the bearing contact due to the orbital motion of the rolling elements. A numerical method is developed to determine the full bearing stiffness matrix corresponding to two radial, one axial, and two angular coordinates; the rotation about the shaft axis is free by design. This proposed stiffness determination method is validated against experiments in the literature and compared to existing analytical models and widely used advanced computational methods. The fully-populated stiffness matrix demonstrates the coupling between bearing radial, axial, and tilting bearing deflections.

  17. Bear-inflicted human injury and fatality.

    PubMed

    Floyd, T

    1999-01-01

    This review attempts to summarize credible scientific information, and to dispel myths, regarding bear attacks. Publications in the scientific literature were sought through a Medline search and by reviewing the bibliographies of related books and scientific articles. Personal experience and interviews with authorities were also used in preparation of this review, although only published articles or books are cited. This is a summary of case series reported or observed elsewhere. Bear-inflicted human injury and death is rare. Brown bear attacks tend to be severe and to occur suddenly, without provocation. Black bear attacks usually result in minor injuries and tend to be predacious. Polar bear attacks are exceedingly rare, and the ferocity of polar bears has probably been overemphasized. Bear-inflicted wounds should be treated as major trauma in accordance with advanced trauma life support guidelines. This information may be useful in counseling patients with regard to prevention of injury or death from bear attack.

  18. Happy Birthday Smokey Bear from Joe Acaba

    NASA Image and Video Library

    Expedition 32 Flight Engineer Joe Acaba wishes Smokey Bear a Happy Birthday. For 68 years Smokey Bear has been promoting fire safety and prevention through the message, “Only You Can Prevent Wild...

  19. Improved transducer for squeeze-film bearings

    NASA Technical Reports Server (NTRS)

    Hoogenbloom, L.

    1971-01-01

    Transducer amplifies vibrations produced by piezoelectric drivers, creating greater amplitudes than were possible with direct drive devices. Drivers isolated from bearing surfaces result in bearings with high axial load capacity and stiffness, thus, wear on ceramic cylinders is reduced.

  20. NK depletion results in increased CCL22 secretion and Treg levels in Lewis lung carcinoma via the accumulation of CCL22-secreting CD11b+CD11c+ cells.

    PubMed

    Mailloux, Adam W; Clark, Anna-Maria A; Young, M Rita I

    2010-12-01

    Tumor-induced immune suppression involves the accumulation of suppressive infiltrates in the tumor microenvironment such as regulatory T-cells (Tregs). Previous studies demonstrated that NK-dependant increases in CCL22 secretion selectively recruit Tregs toward murine lungs bearing Lewis Lung Carcinoma (LLC). To extend the in vitro studies, the present studies utilized in vivo depletion of NK cells to ascertain the contribution of NK-derived CCL22 toward total CCL22 and subsequent Treg levels in both normal and LLC-bearing lungs. However, NK depletion had the unexpected effect of increasing both CCL22 secretion and Treg levels in the lungs of NK-depleted LLC-bearing mice. This was concurrent with an increase in tumor burden. Flow cytometry and a series of both immunomagnetic and FACS isolations were used to identify the CCL22-producing cellular fractions in LLC-bearing lungs. A novel CD11b(+)CD11c(+) cell population was identified that accumulates in large numbers in NK-depleted LLC-bearing lung tissue. These CD11b(+)CD11c(+) cells secreted large amounts of CCL22 that may overcompensate for the loss of NK-derived CCL22 in the lungs of NK-depleted LLC-bearing mice. Taken together, these data suggest that NK cells play both a positive and negative role in the regulation of CCL22 secretion and, in turn, the recruitment of Tregs toward LLC-bearing lungs.

  1. Stable isotopes to detect food-conditioned bears and to evaluate human-bear management

    USGS Publications Warehouse

    Hopkins, John B.; Koch, Paul L.; Schwartz, Charles C.; Ferguson, Jake M.; Greenleaf, Schuyler S.; Kalinowski, Steven T.

    2012-01-01

    We used genetic and stable isotope analysis of hair from free-ranging black bears (Ursus americanus) in Yosemite National Park, California, USA to: 1) identify bears that consume human food, 2) estimate the diets of these bears, and 3) evaluate the Yosemite human–bear management program. Specifically, we analyzed the isotopic composition of hair from bears known a priori to be food-conditioned or non-food-conditioned and used these data to predict whether bears with an unknown management status were food-conditioned (FC) or non-food-conditioned (NFC). We used a stable isotope mixing model to estimate the proportional contribution of natural foods (plants and animals) versus human food in the diets of FC bears. We then used results from both analyses to evaluate proactive (population-level) and reactive (individual-level) human–bear management, and discussed new metrics to evaluate the overall human–bear management program in Yosemite. Our results indicated that 19 out of 145 (13%) unknown bears sampled from 2005 to 2007 were food-conditioned. The proportion of human food in the diets of known FC bears likely declined from 2001–2003 to 2005–2007, suggesting proactive management was successful in reducing the amount of human food available to bears. In contrast, reactive management was not successful in changing the management status of known FC bears to NFC bears, or in reducing the contribution of human food to the diets of FC bears. Nine known FC bears were recaptured on 14 occasions from 2001 to 2007; all bears were classified as FC during subsequent recaptures, and human–bear management did not reduce the amount of human food in the diets of FC bears. Based on our results, we suggest Yosemite continue implementing proactive human–bear management, reevaluate reactive management, and consider removing problem bears (those involved in repeated bear incidents) from the population.

  2. Warning Signs of Lung Disease

    MedlinePlus

    ... Warning Signs of Lung Disease Warning Signs of Lung Disease A nagging cough or slight wheeze may ... prepare for you next office visit. Questions about Lung Health? Call our Lung HelpLine. Get free counseling ...

  3. Mercury in polar bears from Alaska

    SciTech Connect

    Lentfer, J.W.; Galster, W.A.

    1987-04-01

    Alaskan polar bear (Ursus maritimus) muscle and liver samples collected in 1972 were analyzed for total mercury. Bears north of Alaska had more mercury than bears west of Alaska. The only difference between young and adult animals was in the northern area where adults had more mercury in liver tissue than young animals. Levels were probably not high enough to be a serious threat to bears.

  4. Human impacts on bear habitat use

    USGS Publications Warehouse

    Mattson, David J.

    1990-01-01

    : Human effects on bear habitat use are mediated through food biomass changes, bear tolerance of humans and their impacts, and human tolerance of bears. Large-scale changes in bear food biomass have been caused by conversion of wildlands and waterways to intensive human use, and by the introduction of exotic pathogens. Bears consume virtually all human foods that have been established in former wildlands, but bear use has been limited by access. Air pollution has also affected bear food biomass on a small scale and is likely to have major future impacts on bear habitat through climatic warming. Major changes in disturbance cycles and landscape mosaics wrought by humans have further altered temporal and spatial pulses of bear food production. These changes have brought short-term benefits in places, but have also added long-term stresses to most bear populations. Although bears tend to avoid humans, they will also use exotic and native foods in close proximity to humans. Subadult males and adult females are more often impelled to forage closer to humans because of their energetic predicament and because more secure sites are often preempted by adult males. Although male bears are typically responsible for most livestock predation, adult females and subadult males are more likely to be habituated to humans because they tend to forage closer to humans. Elimination of human-habituated bears predictably reduces effective carrying capacity and is more likely to be a factor in preserving bear populations where humans are present in moderate-to-high densities. If humans desire to preserve viable bear populations, they will either have to accept increased risk of injury associated with preserving habituated animals, or continue to crop habituated bears while at the same time preserving large tracts of wildlands free from significant human intrusion.

  5. Dynamic Tester For Rotor Seals And Bearings

    NASA Technical Reports Server (NTRS)

    Von Pragenau, George L.

    1991-01-01

    Simplified apparatus measures performance under vibration. Measures some of dynamic parameters of rotor seals and bearings. Tests damping seals, damping bearings, conventional seals, and conventional bearings. Used with variety of pumped liquids, from water to liquid oxygen or hydrogen. Designed to test bearings and seals of turbopumps, tester rotates shaft at high speed while liquid flows much as it would in real turbopump. Also measures deflections of components.

  6. Characterization of Fault Size in Bearings

    DTIC Science & Technology

    2014-12-23

    Characterization of Fault Size in Bearings Matan Mendelovich 1, Yitschak Sanders 1, Gideon Kogan 1, Mor Battat 1, Dr. Renata Klein 2, and Prof...D.N. Misgav 20103, Israel Renata.Klein@RKDiagnostics.co.il ABSTRACT Bearings are important components in rotating machines. An initial small...damage in the bearing may cause a fast degradation, which may lead to the machine breakdown. The health condition of bearings can be monitored using

  7. Research In Diagnosing Bearing Defects From Vibrations

    NASA Technical Reports Server (NTRS)

    Zoladz, T.; Earhart, E.; Fiorucci, T.

    1995-01-01

    Report describes research in bearing-defect signature analysis - use of vibration-signal analysis to diagnose defects in roller and ball bearings. Experiments performed on bearings in good condition and other bearings in which various parts scratched to provide known defects correlated with vibration signals. Experiments performed on highly instrumented motor-driven rotor assembly at speeds up to 10,050 r/min, using accelerometers, velocity probes, and proximity sensors mounted at various locations on assembly to measure vibrations.

  8. Dynamic Tester For Rotor Seals And Bearings

    NASA Technical Reports Server (NTRS)

    Von Pragenau, George L.

    1991-01-01

    Simplified apparatus measures performance under vibration. Measures some of dynamic parameters of rotor seals and bearings. Tests damping seals, damping bearings, conventional seals, and conventional bearings. Used with variety of pumped liquids, from water to liquid oxygen or hydrogen. Designed to test bearings and seals of turbopumps, tester rotates shaft at high speed while liquid flows much as it would in real turbopump. Also measures deflections of components.

  9. Thin film superconductor magnetic bearings

    DOEpatents

    Weinberger, Bernard R.

    1995-12-26

    A superconductor magnetic bearing includes a shaft (10) that is subject to a load (L) and rotatable around an axis of rotation, a magnet (12) mounted to the shaft, and a stator (14) in proximity to the shaft. The stator (14) has a superconductor thin film assembly (16) positioned to interact with the magnet (12) to produce a levitation force on the shaft (10) that supports the load (L). The thin film assembly (16) includes at least two superconductor thin films (18) and at least one substrate (20). Each thin film (18) is positioned on a substrate (20) and all the thin films are positioned such that an applied magnetic field from the magnet (12) passes through all the thin films. A similar bearing in which the thin film assembly (16) is mounted on the shaft (10) and the magnet (12) is part of the stator (14) also can be constructed.

  10. 14 CFR 27.623 - Bearing factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Bearing factors. 27.623 Section 27.623... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction General § 27.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

  11. 14 CFR 23.623 - Bearing factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Bearing factors. 23.623 Section 23.623... Bearing factors. (a) Each part that has clearance (free fit), and that is subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of normal relative motion. (b) For...

  12. 14 CFR 29.623 - Bearing factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Bearing factors. 29.623 Section 29.623... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.623 Bearing factors. (a... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

  13. 14 CFR 25.623 - Bearing factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Bearing factors. 25.623 Section 25.623... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

  14. Lightweight, high speed bearing balls: A concept

    NASA Technical Reports Server (NTRS)

    Parker, R. J.

    1974-01-01

    Low mass bearing balls with hardened iron-plated surfaces can eliminate problems of low fatigue strength and flexure fatigue, and lead to increased life and reliability of high speed ball bearings. Low mass balls exert lower centrifugal forces on outer race of bearing thus eliminating detrimental effect of high speed operation.

  15. Bearing-Mounting Concept Accommodates Thermal Expansion

    NASA Technical Reports Server (NTRS)

    Nespodzany, Robert; Davis, Toren S.

    1995-01-01

    Pins or splines allow radial expansion without slippage. Design concept for mounting rotary bearing accommodates differential thermal expansion between bearing and any structure(s) to which bearing connected. Prevents buildup of thermal stresses by allowing thermal expansion to occur freely but accommodating expansion in such way not to introduce looseness. Pin-in-slot configuration also maintains concentricity.

  16. Cool Polar Bears: Dabbing on the Texture

    ERIC Educational Resources Information Center

    O'Connell, Jean

    2011-01-01

    In this article, the author describes how her second-graders created their cool polar bears. The students used the elements of shape and texture to create the bears. They used Monet's technique of dabbing paint so as to give the bear some texture on his fur.

  17. Teaching American History with Teddy's Bear.

    ERIC Educational Resources Information Center

    Forman-Brunell, Miriam

    2001-01-01

    Discusses the origins of "Teddy's bear," tracing back to a cartoon published in 1902. States that Teddy's bear can shed light on U.S. culture and society. Focuses on the role of Teddy's bear as a symbol of conservationism, an embodiment of male dominance and female nurturance, and a manifestation of white racial supremacy. (CMK)

  18. 14 CFR 25.623 - Bearing factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 25.623 Section 25.623... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

  19. 49 CFR 229.64 - Plain bearings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Plain bearings. 229.64 Section 229.64 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....64 Plain bearings. A plain bearing box shall contain visible free oil and may not be cracked to the...

  20. 14 CFR 27.623 - Bearing factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 27.623 Section 27.623... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction General § 27.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

  1. 14 CFR 23.623 - Bearing factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 23.623 Section 23.623... Bearing factors. (a) Each part that has clearance (free fit), and that is subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of normal relative motion. (b) For...

  2. 14 CFR 29.623 - Bearing factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 29.623 Section 29.623... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.623 Bearing factors. (a... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

  3. Teaching American History with Teddy's Bear.

    ERIC Educational Resources Information Center

    Forman-Brunell, Miriam

    2001-01-01

    Discusses the origins of "Teddy's bear," tracing back to a cartoon published in 1902. States that Teddy's bear can shed light on U.S. culture and society. Focuses on the role of Teddy's bear as a symbol of conservationism, an embodiment of male dominance and female nurturance, and a manifestation of white racial supremacy. (CMK)

  4. Cool Polar Bears: Dabbing on the Texture

    ERIC Educational Resources Information Center

    O'Connell, Jean

    2011-01-01

    In this article, the author describes how her second-graders created their cool polar bears. The students used the elements of shape and texture to create the bears. They used Monet's technique of dabbing paint so as to give the bear some texture on his fur.

  5. 49 CFR 229.64 - Plain bearings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Plain bearings. 229.64 Section 229.64 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....64 Plain bearings. A plain bearing box shall contain visible free oil and may not be cracked to...

  6. 14 CFR 29.623 - Bearing factors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Bearing factors. 29.623 Section 29.623... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.623 Bearing factors. (a... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects...

  7. 14 CFR 29.623 - Bearing factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Bearing factors. 29.623 Section 29.623... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.623 Bearing factors. (a... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects...

  8. 14 CFR 25.623 - Bearing factors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Bearing factors. 25.623 Section 25.623... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects...

  9. 14 CFR 23.623 - Bearing factors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Bearing factors. 23.623 Section 23.623... Bearing factors. (a) Each part that has clearance (free fit), and that is subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of normal relative motion. (b)...

  10. 49 CFR 229.64 - Plain bearings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Plain bearings. 229.64 Section 229.64 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....64 Plain bearings. A plain bearing box shall contain visible free oil and may not be cracked to...

  11. 49 CFR 229.64 - Plain bearings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Plain bearings. 229.64 Section 229.64 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....64 Plain bearings. A plain bearing box shall contain visible free oil and may not be cracked to...

  12. 14 CFR 23.623 - Bearing factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Bearing factors. 23.623 Section 23.623... Bearing factors. (a) Each part that has clearance (free fit), and that is subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of normal relative motion. (b)...

  13. 49 CFR 229.64 - Plain bearings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Plain bearings. 229.64 Section 229.64 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....64 Plain bearings. A plain bearing box shall contain visible free oil and may not be cracked to...

  14. 14 CFR 27.623 - Bearing factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Bearing factors. 27.623 Section 27.623... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction General § 27.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects...

  15. 14 CFR 25.623 - Bearing factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Bearing factors. 25.623 Section 25.623... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects...

  16. 14 CFR 25.623 - Bearing factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Bearing factors. 25.623 Section 25.623... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects...

  17. 14 CFR 23.623 - Bearing factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Bearing factors. 23.623 Section 23.623... Bearing factors. (a) Each part that has clearance (free fit), and that is subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of normal relative motion. (b)...

  18. 14 CFR 29.623 - Bearing factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Bearing factors. 29.623 Section 29.623... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.623 Bearing factors. (a... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects...

  19. 14 CFR 27.623 - Bearing factors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Bearing factors. 27.623 Section 27.623... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction General § 27.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects...

  20. 14 CFR 27.623 - Bearing factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Bearing factors. 27.623 Section 27.623... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction General § 27.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects...

  1. Effects of Bearing Clearance on Turbopump Stability

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Effects of bearing clearances, or "dead bands," on bearing loads and rotor stability in turbopumps examined in a 194-page report. Relatively simple mathematical force model for analyzing effects highlighted. Report shows nonlinear characteristics resulting from bearing dead bands have significant effect on dynamics of turbomachinery and not ignored as in the past.

  2. Foil bearing lubrication theory including compressibility effects

    NASA Technical Reports Server (NTRS)

    Gorla, Rama Subba Reddy; Catalano, Daniel A.

    1987-01-01

    An analysis is presented to determine the film thickness in a foil bearing. Using the Reynolds equation and including the compressibility effects of the gas, an equation was developed applicable to the film thickness in a foil bearing. The bearing was divided into three regions, namely, the entrance region, middle region and exit region. Solutions are obtained for the film thickness in each region.

  3. Passive Thermal Management of Foil Bearings

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert J. (Inventor)

    2015-01-01

    Systems and methods for passive thermal management of foil bearing systems are disclosed herein. The flow of the hydrodynamic film across the surface of bearing compliant foils may be disrupted to provide passive cooling and to improve the performance and reliability of the foil bearing system.

  4. Hydrodynamic squeeze-film bearings for gyroscopes

    NASA Technical Reports Server (NTRS)

    Chiang, T.; Smith, R. L.

    1970-01-01

    Experimental tests are conducted on squeeze-film bearings by applying electricity to piezoelectric ceramics, causing vibrations at thousands or millions of Hz that are amplified and transmitted to the bearing. Rotor operation through 24,000 rpm without whirl instability proved bearing ability to support rotor weight without hydrodynamic action.

  5. High Fracture Toughness Bearing Development

    DTIC Science & Technology

    1981-12-01

    AFWAL-TR-81-2042 C• ) HIGH FRACTURE TOUGHNESS BEARING DEVELOPMENT SKF Industries, Inc. King of Prussia, PA 19406 December 1981 Final Report for...withthe contractor SKF who wrote the report and found that the inclusion of the proprietary notice was ati oversight on their part. The con-tractor and...TASK SKF Industries, Inc . AREA & WORK UNIT NUMBERS 1100 First Avenue 3048 06 07 King of Prussia, PA 19406 It. CONTROLLING OFFICE NAME AND ADDRESS 12

  6. Rolling element bearings in space

    NASA Technical Reports Server (NTRS)

    Kannel, J. W.; Dufrane, K. F.

    1986-01-01

    Some of the advances in tribology that have been associated with aerospace mechanisms are discussed. The needs of aerospace have been the dominant forces leading to improvements in understanding and applying tribology technology. In the past two decades improvements in understanding bearing torque, elastohydrodynamic lubrication, lubricant distribution, cage stability, and transfer film lubricants have been made. It is anticipated that further developments will be made in response to future aerospace requirements.

  7. Analytical solution approximation for bearing

    NASA Astrophysics Data System (ADS)

    Hanafi, Lukman; Mufid, M. Syifaul

    2017-08-01

    The purpose of lubrication is to separate two surfaces sliding past each other with a film of some material which can be sheared without causing any damage to the surfaces. Reynolds equation is a basic equation for fluid lubrication which is applied in the bearing problem. This equation can be derived from Navier-Stokes equation and continuity equation. In this paper Reynolds equation is solved using analytical approximation by making simplification to obtain pressure distribution.

  8. Magnetic bearings for vibration control

    NASA Technical Reports Server (NTRS)

    Schweitzer, G.

    1985-01-01

    A survey is presented on the research of the Institute of Mechanics of the ETH in the field of vibration control with magnetic bearings. It shows a method for modelling an elastic rotor so that it can be represented by a low order model amenable to control techniques. It deals with the control law and spill-over effects, and it also discusses experimental results for an active resonance damper.

  9. Lung needle biopsy

    MedlinePlus

    ... if you have certain lung diseases such as emphysema. Usually, a collapsed lung after a biopsy does ... any type Bullae (enlarged alveoli that occur with emphysema) Cor pulmonale (condition that causes the right side ...

  10. Lungs and Respiratory System

    MedlinePlus

    ... Your 1- to 2-Year-Old Lungs and Respiratory System KidsHealth > For Parents > Lungs and Respiratory System A ... ll have taken at least 600 million breaths. Respiratory System Basics All of this breathing couldn't happen ...

  11. Ex vivo lung perfusion

    PubMed Central

    Machuca, Tiago N.

    2014-01-01

    Lung transplantation (LTx) is an established treatment option for eligible patients with end-stage lung disease. Nevertheless, the imbalance between suitable donor lungs available and the increasing number of patients considered for LTx reflects in considerable waitlist mortality. Among potential alternatives to address this issue, ex vivo lung perfusion (EVLP) has emerged as a modern preservation technique that allows for more accurate lung assessment and also improvement of lung function. Its application in high-risk donor lungs has been successful and resulted in safe expansion of the donor pool. This article will: (I) review the technical details of EVLP; (II) the rationale behind the method; (III) report the worldwide clinical experience with the EVLP, including the Toronto technique and others; (IV) finally, discuss the growing literature on EVLP application for donation after cardiac death (DCD) lungs. PMID:25132972

  12. Lung cancer screening update

    PubMed Central

    Dhillon, Samjot Singh; Loewen, Gregory; Jayaprakash, Vijayvel; Reid, Mary E.

    2013-01-01

    Lung cancer is the leading cause of cancer-related mortality globally and the American cancer society estimates approximately 226,160 new cases and 160,340 deaths from lung cancer in the USA in the year 2012. The majority of lung cancers are diagnosed in the later stages which impacts the overall survival. The 5-year survival rate for pathological st age IA lung cancer is 73% but drops to only 13% for stage IV. Thus, early detection through screening and prevention are the keys to reduce the global burden of lung cancer. This article discusses the current state of lung cancer screening, including the results of the National Lung Cancer Screening Trial, the consideration of implementing computed tomography screening, and a brief overview of the role of bronchoscopy in early detection and potential biomarkers that may aid in the early diagnosis of lung cancer. PMID:23599684

  13. Interstitial Lung Disease

    MedlinePlus

    ... Critical Care & Sleep Medicine Interstitial Lung Disease Program Sarcoidosis Program Autoimmune Lung Center Rebecca C. Keith, MD, ... Syndromes Hypersensitivity Pneumonitis LAM Lupus Rheumatoid Arthritis (RA) Sarcoidosis Overview Scleroderma (SSC) Systemic Vasculitis Reasons to Visit ...

  14. Lung gallium scan

    MedlinePlus

    ... the lungs. This is most often due to sarcoidosis or a certain type of pneumonia. Normal Results ... it may mean any of the following problems: Sarcoidosis (disease in which inflammation occurs in the lungs ...

  15. Fault Tolerant Homopolar Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Li, Ming-Hsiu; Palazzolo, Alan; Kenny, Andrew; Provenza, Andrew; Beach, Raymond; Kascak, Albert

    2003-01-01

    Magnetic suspensions (MS) satisfy the long life and low loss conditions demanded by satellite and ISS based flywheels used for Energy Storage and Attitude Control (ACESE) service. This paper summarizes the development of a novel MS that improves reliability via fault tolerant operation. Specifically, flux coupling between poles of a homopolar magnetic bearing is shown to deliver desired forces even after termination of coil currents to a subset of failed poles . Linear, coordinate decoupled force-voltage relations are also maintained before and after failure by bias linearization. Current distribution matrices (CDM) which adjust the currents and fluxes following a pole set failure are determined for many faulted pole combinations. The CDM s and the system responses are obtained utilizing 1D magnetic circuit models with fringe and leakage factors derived from detailed, 3D, finite element field models. Reliability results are presented vs. detection/correction delay time and individual power amplifier reliability for 4, 6, and 7 pole configurations. Reliability is shown for two success criteria, i.e. (a) no catcher bearing contact following pole failures and (b) re-levitation off of the catcher bearings following pole failures. An advantage of the method presented over other redundant operation approaches is a significantly reduced requirement for backup hardware such as additional actuators or power amplifiers.

  16. Skeletal manifestations of bear scavenging.

    PubMed

    Carson, E A; Stefan, V H; Powell, J F

    2000-05-01

    In many partially or fully skeletonized forensic cases, postmortem animal damage is simply attributed to rodents or carnivores; little effort is made to determine the general size or assign a genus to the scavenger. As one of the largest wild carnivores to inhabit mountainous and forested areas throughout the continental United States, Alaska, and Canada, black bears (Ursus americanus) must be considered possible suspects when skeletonized remains are located showing marks of carnivore damage. Since 1995, three cases of known bear scavenging have been referred to the Maxwell Museum's Laboratory of Human Osteology by the New Mexico Office of the Medical Investigator for skeletal analysis. These cases comprise a total of seven individuals, and all of the remains were deposited in high altitude forests of New Mexico along the western border with Arizona with a minimum of 4 months exposure before recovery. When analyzed, all cases shared a similar pattern of element survivorship and damage. We suggest that bears can be distinguished from members of the canid family, the other common scavenger of human remains, based on the representation of skeletal elements at the scene. Rates and patterns of damage are not as accurate as element recovery in the discrimination of scavenger genus. Use of this information should allow forensic anthropologists to better understand the postmortem taphonomic processes that shaped the skeletal remains, and hopefully prevent misdiagnoses of perimortem trauma on elements not typically scavenged by canids.

  17. Lung cancer prevention.

    PubMed

    Slatore, Christopher; Sockrider, Marianna

    2014-11-15

    Lung cancer is a common form of cancer.There are things you can do to lower your risk of lung cancer. Stop smoking tobacco. Ask your health care provider for help in quitting, including use of medicines to help with nicotine dependence. discuss with your healthcare provider,what you are taking or doing to decrease your risk for lung cancer

  18. Lungs and Respiratory System

    MedlinePlus

    ... A Week of Healthy Breakfasts Shyness Lungs and Respiratory System KidsHealth > For Teens > Lungs and Respiratory System A ... didn't breathe, you couldn't live. Lungs & Respiratory System Basics Each day we breathe about 20,000 ...

  19. Scaling laws for radial foil bearings

    NASA Astrophysics Data System (ADS)

    Honavara Prasad, Srikanth

    The effects of fluid pressurization, structural deformation of the compliant members and heat generation in foil bearings make the design and analysis of foil bearings very complicated. The complex fluid-structural-thermal interactions in foil bearings also make modeling efforts challenging because these phenomena are governed by highly non-linear partial differential equations. Consequently, comparison of various bearing designs require detailed calculation of the flow fields (velocities, pressures), bump deflections (structural compliance) and heat transfer phenomena (viscous dissipation in the fluid, frictional heating, temperature profile etc.,) resulting in extensive computational effort (time/hardware). To obviate rigorous computations and aid in feasibility assessments of foil bearings of various sizes, NASA developed the "rule of thumb" design guidelines for estimation of journal bearing load capacity. The guidelines are based on extensive experimental data. The goal of the current work is the development of scaling laws for radial foil bearings to establish an analytical "rule of thumb" for bearing clearance and bump stiffness. The use of scale invariant Reynolds equation and experimentally observed NASA "rule of thumb" yield scale factors which can be deduced from first principles. Power-law relationships between: a. Bearing clearance and bearing radius, and b. bump stiffness and bearing radius, are obtained. The clearance and bump stiffness values obtained from scaling laws are used as inputs for Orbit simulation to study various cases. As the clearance of the bearing reaches the dimensions of the material surface roughness, asperity contact breaks the fluid film which results in wear. Similarly, as the rotor diameter increases (requiring larger bearing diameters), the load capacity of the fluid film should increase to prevent dry rubbing. This imposes limits on the size of the rotor diameter and consequently bearing diameter. Therefore, this thesis aims

  20. Cannibalism and predation on black bears by grizzly bears in the Yellowstone ecosystem, 1975-1990

    USGS Publications Warehouse

    Mattson, D.J.; Knight, R.R.; Blanchard, B.M.

    1992-01-01

    We documented one instance of an adult male grizzly bear preying upon a black bear and four instances where circumstantial evidence suggested that grizzly bears (two cubs-of-the-year, one yearling female that was injured, and one adult male) had been preyed upon by conspecifics. We also examined feces of grizzly bears for bear remains. Remains of bears tended to be more common in spring feces and did not differ in frequency between early and late years of the study. Our observations generally support existing hypotheses concerning cannibalism among bears.

  1. [Advances in studies on bear bile powder].

    PubMed

    Zhou, Chao-fan; Gao, Guo-jian; Liu, Ying

    2015-04-01

    In this paper, a detailed analysis was made on relevant literatures about bear bile powder in terms of chemical component, pharmacological effect and clinical efficacy, indicating bear bile powder's significant pharmacological effects and clinical application in treating various diseases. Due to the complex composition, bear bile powder is relatively toxic. Therefore, efforts shall be made to study bear bile powder's pharmacological effects, clinical application, chemical composition and toxic side-effects, with the aim to provide a scientific basis for widespread reasonable clinical application of bear bile powder.

  2. Ball Bearing Analysis with the ORBIS Tool

    NASA Technical Reports Server (NTRS)

    Halpin, Jacob D.

    2016-01-01

    Ball bearing design is critical to the success of aerospace mechanisms. Key bearing performance parameters, such as load capability, stiffness, torque, and life all depend on accurate determination of the internal load distribution. Hence, a good analytical bearing tool that provides both comprehensive capabilities and reliable results becomes a significant asset to the engineer. This paper introduces the ORBIS bearing tool. A discussion of key modeling assumptions and a technical overview is provided. Numerous validation studies and case studies using the ORBIS tool are presented. All results suggest the ORBIS code closely correlates to predictions on bearing internal load distributions, stiffness, deflection and stresses.

  3. Extravehicular Space Suit Bearing Technology Development Research

    NASA Astrophysics Data System (ADS)

    Pang, Yan; Liu, Xiangyang; Guanghui, Xie

    2017-03-01

    Pressure bearing has been acting an important role in the EVA (extravehicular activity) suit as a main mobility component. EVA suit bearing has its unique traits on the material, dustproof design, seal, interface, lubrication, load and performance. This paper states the peculiarity and development of the pressure bearing on the construction design element, load and failure mode, and performance and test from the point view of structure design. The status and effect of EVA suit pressure bearing is introduced in the paper. This analysis method can provide reference value for our country’s EVA suit pressure bearing design and development.

  4. Computing Thermal Performances Of Shafts And Bearings

    NASA Technical Reports Server (NTRS)

    Woods, Claudia M.

    1992-01-01

    SHABERTH computer program developed to predict steady-state and transient thermal performance of multi-bearing shaft system operating with either wet or dry friction. Calculates loads, torques, temperatures, and fatigue lives for ball and/or roller bearings on single shaft. Enables study of many causes of instabilities in bearings. Also provides for analysis of reaction of system to termination of supply of lubricant to bearings and other lubricated mechanical elements. Valuable software tool in design and analysis of shaft bearing systems. Written in FORTRAN IV.

  5. Automated Assistance for Designing Active Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Imlach, Joseph

    2008-01-01

    MagBear12 is a computer code that assists in the design of radial, heteropolar active magnetic bearings (AMBs). MagBear12 was developed to help in designing the system described in "Advanced Active-Magnetic-Bearing Thrust-Measurement System". Beyond this initial application, MagBear12 is expected to be useful for designing AMBs for a variety of rotating machinery. This program incorporates design rules and governing equations that are also implemented in other, proprietary design software used by AMB manufacturers. In addition, this program incorporates an advanced unpublished fringing-magnetic-field model that increases accuracy beyond that offered by the other AMB-design software.

  6. Computing Thermal Performances Of Shafts And Bearings

    NASA Technical Reports Server (NTRS)

    Woods, Claudia M.

    1992-01-01

    SHABERTH computer program developed to predict steady-state and transient thermal performance of multi-bearing shaft system operating with either wet or dry friction. Calculates loads, torques, temperatures, and fatigue lives for ball and/or roller bearings on single shaft. Enables study of many causes of instabilities in bearings. Also provides for analysis of reaction of system to termination of supply of lubricant to bearings and other lubricated mechanical elements. Valuable software tool in design and analysis of shaft bearing systems. Written in FORTRAN IV.

  7. Valve assembly having remotely replaceable bearings

    DOEpatents

    Johnson, Evan R.; Tanner, David E.

    1980-01-01

    A valve assembly having remotely replaceable bearings is disclosed wherein a valve disc is supported within a flow duct for rotation about a pair of axially aligned bearings, one of which is carried by a spindle received within a diametral bore in the valve disc, and the other of which is carried by a bearing support block releasably mounted on the duct circumferentially of an annular collar on the valve disc coaxial with its diametrical bore. The spindle and bearing support block are adapted for remote removal to facilitate servicing or replacement of the valve disc support bearings.

  8. Equations For Elastohydrodynamic Lubrication Of Bearings

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1993-01-01

    Equation for thickness of elastohydrodynamic (EHD) lubricant film in rolling-element bearing reduced to simplified form involving only inside and outside diameters of bearing, speed of rotation, parameter related to type of lubricant, and viscosity of lubricant at temperature of bearing. In addition, experimentally derived graph of EHD-film-thickness-reduction factor as function of contact-lubricant-flow number. Accounts for lubricant starvation within Hertzian contact. Graph relating ratio of minimum film thickness to composite roughness of bearing surfaces and to lubrication-life correction factor also provided. Life-correction factor used to determine resultant life of bearing.

  9. Equations For Elastohydrodynamic Lubrication Of Bearings

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1993-01-01

    Equation for thickness of elastohydrodynamic (EHD) lubricant film in rolling-element bearing reduced to simplified form involving only inside and outside diameters of bearing, speed of rotation, parameter related to type of lubricant, and viscosity of lubricant at temperature of bearing. In addition, experimentally derived graph of EHD-film-thickness-reduction factor as function of contact-lubricant-flow number. Accounts for lubricant starvation within Hertzian contact. Graph relating ratio of minimum film thickness to composite roughness of bearing surfaces and to lubrication-life correction factor also provided. Life-correction factor used to determine resultant life of bearing.

  10. Heuristic explanation of journal bearing instability

    NASA Technical Reports Server (NTRS)

    Crandall, S. H.

    1982-01-01

    A fluid-filled journal bearing is viewed as a powerful pump circulating fluid around the annular space between the journal and the bearing. A small whirling motion of the journal generates a wave of thickness variation progressing around the channel. The hypothesis that the fluid flow drives the whirl whenever the mean of the pumped fluid velocity is greater than the peripheral speed of the thickness variation wave is discussed and compared with other simple explanations of journal bearing instability. It is shown that for non-cavitation long bearings the hypothesis predicts instability onset correctly for unloaded bearings but gradually overpredicts the onset speed as the load is increased.

  11. Oncogenic mutation profiling in new lung cancer and mesothelioma cell lines

    PubMed Central

    Lam, David CL; Luo, Susan Y; Deng, Wen; Kwan, Johnny SH; Rodriguez-Canales, Jaime; Cheung, Annie LM; Cheng, Grace HW; Lin, Chi-Ho; Wistuba, Ignacio I; Sham, Pak C; Wan, Thomas SK; Tsao, Sai-Wah

    2015-01-01

    Background Thoracic tumor, especially lung cancer, ranks as the top cancer mortality in most parts of the world. Lung adenocarcinoma is the predominant subtype and there is increasing knowledge on therapeutic molecular targets, namely EGFR, ALK, KRAS, and ROS1, among lung cancers. Lung cancer cell lines established with known clinical characteristics and molecular profiling of oncogenic targets like ALK or KRAS could be useful tools for understanding the biology of known molecular targets as well as for drug testing and screening. Materials and methods Five new cancer cell lines were established from pleural fluid or biopsy tissues obtained from Chinese patients with primary lung adenocarcinomas or malignant pleural mesothelioma. They were characterized by immunohistochemistry, growth kinetics, tests for tumorigenicity, EGFR and KRAS gene mutations, ALK gene rearrangement and OncoSeq mutation profiling. Results These newly established lung adenocarcinoma and mesothelioma cell lines were maintained for over 100 passages and demonstrated morphological and immunohistochemical features as well as growth kinetics of tumor cell lines. One of these new cell lines bears EML4-ALK rearrangement variant 2, two lung cancer cell lines bear different KRAS mutations at codon 12, and known single nucleotide polymorphism variants were identified in these cell lines. Discussion Four new lung adenocarcinoma and one mesothelioma cell lines were established from patients with different clinical characteristics and oncogenic mutation profiles. These characterized cell lines and their mutation profiles will provide resources for exploration of lung cancer and mesothelioma biology with regard to the presence of known oncogenic mutations. PMID:25653542

  12. Atypical endocrine tumors of the lung.

    PubMed

    McDowell, E M; Wilson, T S; Trump, B F

    1981-01-01

    Seven malignant peripheral lung tumors that were diagnosed using light microscopy as large-cell carcinomas or as epidermoid or adenocarcinomas were studied by light and electron microscopic histochemistry. All tumors contained numerous dense-core granules. The cells were joined by desmosomes and contained well-developed tonofilament bundles. Serotonin was demonstrated in six of seven tumors and argyrophilic granules were demonstrated in five of six tumors tested. Four tumors produced mucus. All tumors extended to the visceral pleura and two invaded the chest wall. The existence of lung tumors that contain serotonin and bear argyrophilic putative endocrine granules, but that do not have a light-microscopic histology characteristic of either carcinoid or oat-cell carcinomas, is confirmed. The presumptive endocrine nature of such tumors usually passes unrecognized because they lack criteria to allow diagnosis by routine methods.

  13. Chromatographic (TLC) differentiation of grizzly bear and black bear scats

    USGS Publications Warehouse

    Picton, Harold D.; Kendall, Katherine C.

    1994-01-01

    While past work concluded that thin-layer chromatography (TLC) was inadequate for the separation of grizzly (Ursus arctos horribilis) and black bear (U. americanus) scats, our study found differences adequate for species separation. A key was constructed using 19 of 40 data points recorded on each(N)=356 profiles of 178) know-species scat. Accuracy was best for late summer scats (94%). Methods for specimen preparation, analysis, and reading the TLC profiles are discussed. Factors involved in scat variation were tested.

  14. Wave Journal Bearings Under Dynamic Loads

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C.; Dimofte, Florin

    2002-01-01

    The dynamic behavior of the wave journal bearing was determined by running a three-wave bearing with an eccentrically mounted shaft. A transient analysis was developed and used to predict numerical data for the experimental cases. The three-wave journal bearing ran stably under dynamic loads with orbits well inside the bearing clearance. The orbits were almost circular and nearly free of the influence of, but dynamically dependent on, bearing wave shape. Experimental observations for both the absolute bearing-housing-center orbits and the relative bearing-housing-center-to-shaft-center orbits agreed well with the predictions. Moreover, the subsynchronous whirl motion generated by the fluid film was found experimentally and predicted theoretically for certain speeds.

  15. Pratt and Whitney cryogenic turbopump bearing experience

    NASA Technical Reports Server (NTRS)

    Poole, W. E.; Bursey, R. W., Jr.

    1988-01-01

    Successful, reusable bearings require lubrication, traditionally, a transfer film from sacrificial cage wear. Early testing included materials screening programs to identify suitable cryogenic cage materials. A specially developed element tester that simulated the function of a ball bearing cage was used. Suitable materials must provide lubrication with an acceptably low wear rate, without abrading contacting surfaces. The most promising materials were tested in full scale bearings at speeds up to 4 MDN. Teflon, filled with 40 percent bronze powder, was the best performing material. A variety of bearings were designed and successfully tested in LH2 and LOX. Bearings with bronze filled Teflon cages were successfully tested for 150 hrs. In overload tests, the same design was tested for 5 hrs at maximum Hertz stresses above 450 ksi and an additional 5 hrs with a maximum Hertz stress exceeding 500 ksi. Four bearings were tested in LOX for 25 hrs, with a maximum time per bearing of 10 hrs.

  16. Foil bearing research at Penn State

    NASA Technical Reports Server (NTRS)

    Carpino, Marc

    1993-01-01

    Foil journal bearings consist of a compliant metal shell or foil which supports a rigid journal by means of a fluid film. Foil bearings are considered to be a potential alternative to rolling element or traditional rigid surface bearings in cryogenic turbomachinery applications. The prediction of foil bearing performance requires the coupled solution of the foil deflection and the fluid flow in the bearing clearance between the rotor and the foil. The investigations being conducted in the Department of Mechanical Engineering at Penn State are focused in three areas: theoretical prediction of steady state bearing performance, modeling of the dynamic bearing characteristics to determine performance in rotor systems, and experimental verification of analysis codes. The current status and results from these efforts will be discussed.

  17. Design review of fluid film bearing testers

    NASA Technical Reports Server (NTRS)

    Scharrer, Joseph K.

    1993-01-01

    The designs of three existing testers (Hybrid Bearing Tester, OTV Bearing Tester, and Long Life Bearing Tester) owned by NASA were reviewed for their capability to serve as a multi-purpose cryogenic fluid film bearing tester. The primary tester function is the validation of analytical predictions for fluid film bearing steady state and dynamic performance. Evaluation criteria were established for test bearing configurations, test fluids, instrumentation, and test objectives. Each tester was evaluated with respect to these criteria. A determination was made of design improvements which would allow the testers to meet the stated criteria. The cost and time required to make the design changes were estimated. A recommendation based on the results of this study was made to proceed with the Hybrid Bearing Tester.

  18. Lubrication for high load duplex bearings

    SciTech Connect

    Steinhoff, R.G.

    1997-08-01

    Three ES and H-compatible lubricants (Environment, Safety and Health) for high load duplex bearing applications were evaluated and compared against trichlorotrifluoroethane (Freon) deposition of low molecular weight polytetrafluoroethylene (PTFE) bearing lubricant extracted from Vydax{trademark}. Vydax is a product manufactured by DuPont consisting of various molecular weights of PTFE suspended in trichlorotrifluoroethane (Freon) which is an ozone-depleting solvent. Bearings with Supercritical CO{sub 2} deposition of PTFE extracted from Vydax AR/IPA, bearings with titanium carbide coated balls, and bearings with diamond-like carbon races and retainers were evaluated. Bearings with Supercritical CO{sub 2} deposition of PTFE from Vydax AR/IPA performed as well as bearings with Freon deposition of PTFE from Freon-based Vydax.

  19. Contact Sensors on Ceramic Ball Bearings

    NASA Astrophysics Data System (ADS)

    Yi, Jia; Just-Agosto, Frederick; Romero, Edwar

    2002-01-01

    Integration of micro contact sensors onto a ball bearing is a critical technology necessary for on-line bearing health monitoring in an industrial harsh environment and evaluation of the bearing performance and design. The current planner fabrication methods offered by the MEMS technology restrict the possibility of integrating micro sensor onto a double contoured bearing surface in a more traditional manufacturing environment. We have developed an unique technique to directly fabricate micron-sized pressure and temperature sensors onto a miniature ceramic ball bearing. A complete fabrication process, based on sensor design, surface preparation, optimized sputtering parameters, photolithographic techniques and sensor post-treatment, is described. Pressure and temperature measurement results on a miniature ceramic ball bearing show good correlation with numerical thermal-EHL analysis and good wear resistance. Keywords: Ball Bearing, Thin film Sensor, Pressure sensor, Temperature Sensor, adhesion, wear resistance, Non-developable surface, and thermal-EHL.

  20. The lung in space

    NASA Technical Reports Server (NTRS)

    Prisk, G. Kim

    2005-01-01

    The lung is exquisitely sensitive to gravity, which induces gradients in ventilation, blood flow, and gas exchange. Studies of lungs in microgravity provide a means of elucidating the effects of gravity. They suggest a mechanism by which gravity serves to match ventilation to perfusion, making for a more efficient lung than anticipated. Despite predictions, lungs do not become edematous, and there is no disruption to, gas exchange in microgravity. Sleep disturbances in microgravity are not a result of respiratory-related events; obstructive sleep apnea is caused principally by the gravitational effects on the upper airways. In microgravity, lungs may be at greater risk to the effects of inhaled aerosols.

  1. The lung in space

    NASA Technical Reports Server (NTRS)

    Prisk, G. Kim

    2005-01-01

    The lung is exquisitely sensitive to gravity, which induces gradients in ventilation, blood flow, and gas exchange. Studies of lungs in microgravity provide a means of elucidating the effects of gravity. They suggest a mechanism by which gravity serves to match ventilation to perfusion, making for a more efficient lung than anticipated. Despite predictions, lungs do not become edematous, and there is no disruption to, gas exchange in microgravity. Sleep disturbances in microgravity are not a result of respiratory-related events; obstructive sleep apnea is caused principally by the gravitational effects on the upper airways. In microgravity, lungs may be at greater risk to the effects of inhaled aerosols.

  2. Evaluation of rotating, incompressibly lubricated, pressurized thrust bearings

    NASA Technical Reports Server (NTRS)

    Fleming, D. P.

    1971-01-01

    Program evaluates a series hybrid, fluid film ball bearing consisting of an orifice compensated pressurized thrust bearing in conjunction with a self-acting journal bearing. Oil viscosities corresponding to experimentally measured ball bearing outer-race temperatures were used.

  3. Genomic evidence of geographically widespread effect of gene flow from polar bears into brown bears

    PubMed Central

    Cahill, James A; Stirling, Ian; Kistler, Logan; Salamzade, Rauf; Ersmark, Erik; Fulton, Tara L; Stiller, Mathias; Green, Richard E; Shapiro, Beth

    2015-01-01

    Polar bears are an arctic, marine adapted species that is closely related to brown bears. Genome analyses have shown that polar bears are distinct and genetically homogeneous in comparison to brown bears. However, these analyses have also revealed a remarkable episode of polar bear gene flow into the population of brown bears that colonized the Admiralty, Baranof and Chichagof islands (ABC islands) of Alaska. Here, we present an analysis of data from a large panel of polar bear and brown bear genomes that includes brown bears from the ABC islands, the Alaskan mainland and Europe. Our results provide clear evidence that gene flow between the two species had a geographically wide impact, with polar bear DNA found within the genomes of brown bears living both on the ABC islands and in the Alaskan mainland. Intriguingly, while brown bear genomes contain up to 8.8% polar bear ancestry, polar bear genomes appear to be devoid of brown bear ancestry, suggesting the presence of a barrier to gene flow in that direction. PMID:25490862

  4. Genomic evidence of geographically widespread effect of gene flow from polar bears into brown bears.

    PubMed

    Cahill, James A; Stirling, Ian; Kistler, Logan; Salamzade, Rauf; Ersmark, Erik; Fulton, Tara L; Stiller, Mathias; Green, Richard E; Shapiro, Beth

    2015-03-01

    Polar bears are an arctic, marine adapted species that is closely related to brown bears. Genome analyses have shown that polar bears are distinct and genetically homogeneous in comparison to brown bears. However, these analyses have also revealed a remarkable episode of polar bear gene flow into the population of brown bears that colonized the Admiralty, Baranof and Chichagof islands (ABC islands) of Alaska. Here, we present an analysis of data from a large panel of polar bear and brown bear genomes that includes brown bears from the ABC islands, the Alaskan mainland and Europe. Our results provide clear evidence that gene flow between the two species had a geographically wide impact, with polar bear DNA found within the genomes of brown bears living both on the ABC islands and in the Alaskan mainland. Intriguingly, while brown bear genomes contain up to 8.8% polar bear ancestry, polar bear genomes appear to be devoid of brown bear ancestry, suggesting the presence of a barrier to gene flow in that direction. © 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  5. Development and Evaluation of Titanium Spacesuit Bearings

    NASA Technical Reports Server (NTRS)

    Rhodes, Richard; Battisti, Brian; Ytuarte, Raymond, Jr.; Schultz, Bradley

    2016-01-01

    The Z-2 Prototype Planetary Extravehicular Space Suit Assembly is a continuation of NASA's Z-series of spacesuits, designed with the intent of meeting a wide variety of exploration mission objectives, including human exploration of the Martian surface. Incorporating titanium bearings into the Z-series space suit architecture allows us to reduce mass by an estimated 23 lbs per suit system compared to the previously used stainless steel bearing race designs, without compromising suit functionality. There are two obstacles to overcome when using titanium for a bearing race- 1) titanium is flammable when exposed to the oxygen wetted environment inside the space suit and 2) titanium's poor wear properties are often challenging to overcome in tribology applications. In order to evaluate the ignitability of a titanium space suit bearing, a series of tests were conducted at White Sands Test Facility (WSTF) that introduced the bearings to an extreme test profile, with multiple failures imbedded into the test bearings. The testing showed no signs of ignition in the most extreme test cases; however, substantial wear of the bearing races was observed. In order to design a bearing that can last an entire exploration mission (approx. 3 years), design parameters for maximum contact stress need to be identified. To identify these design parameters, bearing test rigs were developed that allow for the quick evaluation of various bearing ball loads, ball diameters, lubricants, and surface treatments. This test data will allow designers to minimize the titanium bearing mass for a specific material and lubricant combination and design around a cycle life requirement for an exploration mission. This paper reviews the current research and testing that has been performed on titanium bearing races to evaluate the use of such materials in an enriched oxygen environment and to optimize the bearing assembly mass and tribological properties to accommodate for the high bearing cycle life for an

  6. Right paw foraging bias in wild black bear (Ursus americanus kermodei).

    PubMed

    Reimchen, T E; Spoljaric, M A

    2011-07-01

    Using field observations of ~15 wild adult black bear (Ursus americanus kermodei) foraging on a salmon stream during two autumns on the central coast of British Columbia, we tested for laterality of forelimb use during lunging and during handling of salmon. Of 288 lunging events observed overall, 53% were non biased, 26% were right-limb biased, and 21% left-limb biased (p = .53 between left and right bias). Among six bears in which we could ascertain individual identity (182 lunging events), there was heterogeneity among individuals (p <.05) of which two were significantly right biased and one significantly left biased (p<.005). Of 186 carcass-handling (pick-up) events, 68% were right-pawed (p <.005) and there was no heterogeneity among five individually identifiable bears (p = .19). There was no forelimb laterality in adjustment of the prey in the mouth or in securing the prey to the substrate. This is the first report of task-specific behavioural lateralisation of a wild carnivore and is suggestive of a right bias (left-hemisphere dominance) in object manipulation.

  7. Calf stretching in non-weight bearing versus weight bearing.

    PubMed

    Dinh, N V; Freeman, H; Granger, J; Wong, S; Johanson, M

    2011-03-01

    Limited ankle dorsiflexion passive range of motion (DF PROM) has been associated with lower extremity overuse injuries. Therefore, clinicians often prescribe stretching exercises to increase ankle DF PROM. However, there is limited evidence to indicate if any particular gastrocnemius stretching exercise results in greater improvement in DF PROM. The aim of this study was to determine if gastrocnemius stretching in non-weight bearing (NWB) or weight bearing (WB) results in a greater increase of ankle DF PROM. 28 healthy volunteers, aged 18-55 years, who exhibited less than 10 degrees of ankle DF PROM completed the study. Participants were randomized into 2 stretching groups: NWB and WB. Both groups completed a 3-week home gastrocnemius stretching program, consisting of 5 repetitions held for 30 s each, 2 times daily. Participants' ankle DF PROM was measured with a blinded standard goniometer in NWB and WB positions before and after participation in a 3-week home gastrocnemius stretching program. Two 3-way mixed model ANOVAs demonstrated no significant difference in ankle DF PROM between the NWB and WB groups for either the NWB measurement condition (p=0.49) or WB measurement condition (p=0.86). Gastrocnemius stretching exercises performed in NWB or WB were equally effective in increasing ankle DF PROM.

  8. Advances in artificial lungs.

    PubMed

    Ota, Kei

    2010-04-01

    Artificial lungs have already been developed as complete artificial organs, and results of many investigations based on innovative concepts have been reported continuously. In open-heart surgery, artificial lungs are used for extracorporeal circulation to maintain gas exchange, and the commercial products currently available perform adequately, including providing for antithrombogenicity. However, patients after cardiopulmonary arrest or severe respiratory/circulatory failure have required long-term assist with extracorporeal membrane oxygenation (ECMO). The number of artificial lungs used for ECMO in those cases has shown significant growth in recent years. Therefore, it is expected that durability and antithrombogenicity will ensure the prolonged use of an artificial lung for several weeks or months. Furthermore, interests in research are shifting to use of oxygenators as a bridge to lung transplantation and an implantable artificial lung. This paper discusses recent advances in artificial lungs, focusing on the current state and on trends in research and development.

  9. [Lung cancer screening].

    PubMed

    Sánchez González, M

    2014-01-01

    Lung cancer is a very important disease, curable in early stages. There have been trials trying to show the utility of chest x-ray or computed tomography in Lung Cancer Screening for decades. In 2011, National Lung Screening Trial results were published, showing a 20% reduction in lung cancer mortality in patients with low dose computed tomography screened for three years. These results are very promising and several scientific societies have included lung cancer screening in their guidelines. Nevertheless we have to be aware of lung cancer screening risks, such as: overdiagnosis, radiation and false positive results. Moreover, there are many issues to be solved, including choosing the appropriate group to be screened, the duration of the screening program, intervals between screening and its cost-effectiveness. Ongoing trials will probably answer some of these questions. This article reviews the current evidence on lung cancer screening.

  10. Hydrostatic bearings for a turbine fluid flow metering device

    DOEpatents

    Fincke, J.R.

    1980-05-02

    A rotor assembly fluid metering device has been improved by development of a hydrostatic bearing fluid system which provides bearing fluid at a common pressure to rotor assembly bearing surfaces. The bearing fluid distribution system produces a uniform film of fluid distribution system produces a uniform film of fluid between bearing surfaces and allows rapid replacement of bearing fluid between bearing surfaces, thereby minimizing bearing wear and corrosion.

  11. Transfer Lubrication For Cryogenic Bearings

    NASA Technical Reports Server (NTRS)

    Barber, S. A.; Kannel, J. W.; Dufrane, K. F.

    1988-01-01

    Report presents evaluation of bronze-filled polytetrafluoroethylene (PTFE), known as Salox M, as cage material for ball bearings in high-pressure turbopumps for liquid oxygen. Material evaluated as potentially longer-lived replacement for glass-filled PTFE, known as Armalon. Cage transfers PTFE to balls to form solid lubricant film. However, glass fibers in glass-filled material tend to interfere with transfer. Two cage-design concepts developed; one involves metal-reinforced cage of bronze-filled PTFE; other calls for bronze-filled PTFE inserts in metal structure.

  12. Current leads and magnetic bearings

    SciTech Connect

    Hull, J.R.

    1993-12-31

    Since the discovery of high-temperature superconductors (HTSs), Argonne National Laboratory (ANL) has been active in a broad spectrum of activities in developing these materials for applications. Work at every stage of development has involved industrial collaboration in order to accelerate commercialization. While most of the development work has been devoted to improving the properties of current-carrying wires, some effort has been devoted to applications that can utilize HTSs with properties available now or in the near future. In this paper, I discuss advances made at my laboratory in the area of current leads and magnetic bearings.

  13. Current leads and magnetic bearings

    NASA Astrophysics Data System (ADS)

    Hull, J. R.

    1993-10-01

    Since the discovery of high temperature superconductors (HTS's), Argonne National Laboratory (ANL) has been active in a broad spectrum of activities in developing these materials for applications. Work at every stage of development has involved industrial collaboration in order to accelerate commercialization. While most of the development work has been devoted to improving the properties of current-carrying wires, some effort has been devoted to applications that can utilize HTS's with properties available now or in the near future. In this paper, advances made in the area of current leads and magnetic bearings are discussed.

  14. Gas Foil Bearing Development Program.

    DTIC Science & Technology

    1981-09-01

    curve For the 12 -Foil Bearing. 58 8 1 0 MEASURED DATA - ~- w 3 0 CALCULATED DATA S2 0 0 10 20 30 40 50 60 70 s0 90 100 LOAD, LB Figure 29. Comparison...Government drawings, specifications, or other data are used for any purpose other than in connection with a definitely related Government procurement...formulated, furnished, or in any way supplied the said drawings, specifications, or other data , is not to be regarded by implication or otherwise as in any

  15. Precision magnetic suspension linear bearing

    NASA Technical Reports Server (NTRS)

    Trumper, David L.; Queen, Michael A.

    1992-01-01

    We have shown the design and analyzed the electromechanics of a linear motor suitable for independently controlling two suspension degrees of freedom. This motor, at least on paper, meets the requirements for driving an X-Y stage of 10 Kg mass with about 4 m/sq sec acceleration, with travel of several hundred millimeters in X and Y, and with reasonable power dissipation. A conceptual design for such a stage is presented. The theoretical feasibility of linear and planar bearings using single or multiple magnetic suspension linear motors is demonstrated.

  16. Anergy-like immunosuppression in mice bearing pulmonary foreign-body granulomatous inflammation.

    PubMed Central

    Allred, D. C.; Kobayashi, K.; Yoshida, T.

    1985-01-01

    Pulmonary granulomas were induced in BALB/c mice by the intratracheal injection of insoluble polymerized dextran and latex microparticles. Very large granulomas developed around dextran beads, which reached peak intensity within 2-3 days and rapidly declined in size thereafter. Latex beads generated small stable lesions. The involvement of cell-mediated immunity could not be demonstrated in the inflammatory responses induced by either type of bead. Antigen-induced delayed type hypersensitivity (DTH) and mitogen-induced DTH-like footpad reactions were markedly suppressed in immunized mice bearing early dextran granulomas. Mitogen-induced DTH-like footpad reactions were suppressed in unimmunized animals bearing early dextran foreign-body granulomas. Antigen- and mitogen-induced footpad swelling recovered to normal levels as dextran granulomas diminished in size. No suppression of these footpad reactions was observed in mice bearing small latex foreign-body granulomas. The intraperitoneal injection of aqueous extracts prepared from the lungs of unimmunized donor animals bearing early dextran foreign-body granulomas could partially transfer suppression of mitogen DTH-like footpad responses to normal mice. These results suggest that cells within large, nonimmunologic lung granulomas produce a soluble factor which participates in the expression of anergy-like immunosuppression. Images Figure 2 PMID:3907366

  17. Lung cancer in rats exposed to fibrogenic dusts

    SciTech Connect

    Holland, L.M.; Wilson, J.S.; Tillery, M.I.; Smith, D.M.

    1984-01-01

    Fischer-344 rats were exposed to quartz dusts and to quartz-bearing oil shale dusts in long-term inhalation studies. Aerosol concentrations of 12 mg/m/sup 3/ and 152-176 mg/m/sup 3/ for quartz and shale dusts, respectively, were used in exposure regimens lasting up to two years. Pulmonary fibrosis was observed in most animals surviving beyond 400 days. Adenocarcinomas and epidermoid carcinomas of the lung were observed in animals from all exposure groups, including those exposed to quartz alone. The pulmonary tumors were a late effect, with the earliest lung tumor being observed after 651 days. 13 references, 10 figures, 4 tables.

  18. Aerosol administration of phospho-sulindac inhibits lung tumorigenesis.

    PubMed

    Cheng, Ka Wing; Wong, Chi C; Alston, Ninche; Mackenzie, Gerardo G; Huang, Liqun; Ouyang, Nengtai; Xie, Gang; Wiedmann, Timothy; Rigas, Basil

    2013-08-01

    Phospho-sulindac is a sulindac derivative with promising anticancer activity in lung cancer, but its limited metabolic stability presents a major challenge for systemic therapy. We reasoned that inhalation delivery of phospho-sulindac might overcome first-pass metabolism and produce high levels of intact drug in lung tumors. Here, we developed a system for aerosolization of phospho-sulindac and evaluated the antitumor efficacy of inhaled phospho-sulindac in an orthotopic model of human non-small cell lung cancer (A549 cells). We found that administration by inhalation delivered high levels of phospho-sulindac to the lungs and minimized its hydrolysis to less active metabolites. Consequently, inhaled phospho-sulindac (6.5 mg/kg) was highly effective in inhibiting lung tumorigenesis (75%; P < 0.01) and significantly improved the survival of mice bearing orthotopic A549 xenografts. Mechanistically, phospho-sulindac suppressed lung tumorigenesis by (i) inhibiting EGF receptor (EGFR) activation, leading to profound inhibition of Raf/MEK/ERK and PI3K/AKT/mTOR survival cascades; (ii) inducing oxidative stress, which provokes the collapse of mitochondrial membrane potential and mitochondria-dependent cell death; and (iii) inducing autophagic cell death. Our data establish that inhalation delivery of phospho-sulindac is an efficacious approach to the control of lung cancer, which merits further evaluation.

  19. Comparison of Alignment Correction Angles Between Fixed-Bearing and Mobile-Bearing UKA.

    PubMed

    Inoue, Atsuo; Arai, Yuji; Nakagawa, Shuji; Inoue, Hiroaki; Yamazoe, Shoichi; Kubo, Toshikazu

    2016-01-01

    Good outcomes have been reported with both fixed-bearing and mobile-bearing unicompartmental knee arthroplasty (UKA). However, overcorrected alignment could induce the progression of arthritis on the non-arthroplasty side. Changes of limb alignment after UKA with both types of bearings (fixed bearing: 24 knees, mobile bearing: 28 knees) were investigated. The mean difference between the preoperative standing femoral-tibial angle (FTA) and postoperative standing FTA was significantly larger in mobile bearing UKA group. In fixed-bearing UKA, there must be some laxity in MCL tension so that a 2-mm tension gauge can be inserted. In mobile-bearing UKA, appropriate MCL tension is needed to prevent bearing dislocation. This difference in MCL tension may have caused the difference in the correction angle between the groups.

  20. Current Status of Hybrid Bearing Damage Detection

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Certo, Joseph M.; Morales, Wilfredo

    2004-01-01

    Advances in material development and processing have led to the introduction of ceramic hybrid bearings for many applications. The introduction of silicon nitride hybrid bearings into the high pressure oxidizer turbopump, on the space shuttle main engine, led NASA to solve a highly persistent and troublesome bearing problem. Hybrid bearings consist of ceramic balls and steel races. The majority of hybrid bearings utilize Si3N4 balls. The aerospace industry is currently studying the use of hybrid bearings and naturally the failure modes of these bearings become an issue in light of the limited data available. In today s turbine engines and helicopter transmissions, the health of the bearings is detected by the properties of the debris found in the lubrication line when damage begins to occur. Current oil debris sensor technology relies on the magnetic properties of the debris to detect damage. Since the ceramic rolling elements of hybrid bearings have no metallic properties, a new sensing system must be developed to indicate the system health if ceramic components are to be safely implemented in aerospace applications. The ceramic oil debris sensor must be capable of detecting ceramic and metallic component damage with sufficient reliability and forewarning to prevent a catastrophic failure. The objective of this research is to provide a background summary on what is currently known about hybrid bearing failure modes and to report preliminary results on the detection of silicon nitride debris, in oil, using a commercial particle counter.

  1. Turbocharger bearing retention and lubrication system

    SciTech Connect

    Gutknecht, D.A.

    1991-12-31

    This patent describes exhausts gas driven turbocharger. It comprises a housing, a shaft within the housing having a longitudinal axis of rotation and a pair of ends, a compressor wheel mounted within the housing on one end of the shaft for rotation therewith, a turbine wheel mounted within the housing on the other end of the shaft for rotation therewith, means for communicating air to the compressor wheel, means for communicating exhaust gas to the turbine wheel to cause the latter to rotate the shaft and the compressor wheel mounted thereon to compress the air communicated to the compressor wheel, and bearing means mounting the shaft for rotation relative to the housing, the bearing means including a bearing outer ring, a bearing inner ring, and ball bearing elements supporting the bearing outer ring on the bearing inner ring, a bearing locating aperture in the bearing outer ring, and an elongated bearing location pin having a longitudinal axis of symmetry extending transversely to the longitudinal axis of the shaft.

  2. Interference Fit Life Factors for Roller Bearings

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

    2008-01-01

    The effect of hoop stresses in reducing cylindrical roller bearing fatigue life was determined for various classes of inner ring interference fit. Calculations were performed for up to seven interference fit classes for each of ten bearing sizes. Each fit was taken at tightest, average and loosest values within the fit class for RBEC-5 tolerance, thus requiring 486 separate analyses. The hoop stresses were superimposed on the Hertzian principal stresses created by the applied radial load to calculate roller bearing fatigue life. The method was developed through a series of equations to calculate the life reduction for cylindrical roller bearings based on interference fit. All calculated lives are for zero initial bearing internal clearance. Any reduction in bearing clearance due to interference fit was compensated by increasing the initial (unmounted) clearance. Results are presented as tables and charts of life factors for bearings with light, moderate and heavy loads and interference fits ranging from extremely light to extremely heavy and for bearing accuracy class RBEC 5 (ISO class 5). Interference fits on the inner bearing ring of a cylindrical roller bearing can significantly reduce bearing fatigue life. In general, life factors are smaller (lower life) for bearings running under light load where the unfactored life is highest. The various bearing series within a particular bore size had almost identical interference fit life factors for a particular fit. The tightest fit at the high end of the RBEC-5 tolerance band defined in ANSI/ABMA shaft fit tables produces a life factor of approximately 0.40 for an inner-race maximum Hertz stress of 1200 MPa (175 ksi) and a life factor of 0.60 for an inner-race maximum Hertz stress of 2200 MPa (320 ksi). Interference fits also impact the maximum Hertz stress-life relation.

  3. Methyl sulfone PCB and DDE metabolites in the polar bear (Ursus maritimus) food chain

    SciTech Connect

    Letcher, R.J.; Norstrom, R.J.; Muir, D.C.G.

    1995-12-31

    An important Arctic marine food chain is polar bear, ringed seal (Phoca hispida) and Arctic cod (Boreogadus saida). The Arctic is relatively uncontaminated by chlorinated hydrocarbon contaminants (CHCs). However, high levels of CHCs are bioaccumulated through the marine food web. Methyl sulfone (MeSO{sub 2})-PCB and -DDE metabolites are major CHCs in polar bear, although the proportion of MeSO{sub 2}-PCBs derived from PCB metabolism and/or MeSO{sub 2}-PCB bioaccumulation from the diet is unknown. For this reason, the structure and concentration of MeSO{sup 2}-PCB and -DDE metabolites, PCBs and DDE were determined in whole body Arctic cod, the liver, adipose, lung and muscle of ringed seal and ten tissues of polar bear from the Resolute Bay area of the Canadian Arctic. Preliminary analysis of the ratios of MeSO{sub 2}-PCBs in bear fat and liver to their parent PCBs in seal blubber suggested that CB-49 and CB-87 result in a higher proportion of metabolites in bear than the other PCB congeners, assuming that the MeSO{sup 2}-PCBs are not themselves accumulated from the diet. Bio-availability of the precursor PCBs for subsequent metabolism may also be a factor. The absence in bears of MeSO{sub 2}-metabolites of other metabolizable PCBs in seal may indicate that some MeSO{sub 2}-PCBs are not formed or that they are formed and further metabolized. The MeSO{sub 2}-PCB and -DDE levels and congener patterns among seal and bear tissues and the difference in tissue distribution between species will also be compared. In polar bear, the s-MeSO{sub 2}-PCB to S-PCB and s-MeSO{sub 2}-DDE to DDE ratios were highest in liver, indicating preferred storage.

  4. Rocketdyne LOX bearing tester program

    NASA Technical Reports Server (NTRS)

    Keba, J. E.; Beatty, R. F.

    1988-01-01

    The cause, or causes, for the Space Shuttle Main Engine ball wear were unknown, however, several mechanisms were suspected. Two testers were designed and built for operation in liquid oxygen to empirically gain insight into the problems and iterate solutions in a timely and cost efficient manner independent of engine testing. Schedules and test plans were developed that defined a test matrix consisting of parametric variations of loading, cooling or vapor margin, cage lubrication, material, and geometry studies. Initial test results indicated that the low pressure pump thrust bearing surface distress is a function of high axial load. Initial high pressure turbopump bearing tests produced the wear phenomenon observed in the turbopump and identified an inadequate vapor margin problem and a coolant flowrate sensitivity issue. These tests provided calibration data of analytical model predictions to give high confidence in the positive impact of future turbopump design modification for flight. Various modifications will be evaluated in these testers, since similar turbopump conditions can be produced and the benefit of the modification will be quantified in measured wear life comparisons.

  5. Mechanics of superconducting magnetic bearings

    SciTech Connect

    Chang, Peizen.

    1991-01-01

    Levitation forces and lateral forces in relation to the gaps in superconducting bearings were measured using a beam-and-camera system. Dynamic magnetic stiffness derived from vibration tests were compared to static magnetic stiffness. The relaxation of magnetic forces as a function of time was measured as well. The behavior of levitation forces at temperatures from 4.2 K to 77 K were studied. A rotor equipped with two superconducting bearings was fabricated and was spun up to 120,000 RPM. The drag torques acting on the rotor were measured at both atmospheric pressure and at a partial vacuum of a few mm Hg. Many high-temperature superconductors of different compositions fabricated through different processing techniques were investigated by measuring the magnetic force-gap relationships. The data indicated that YBa{sub 2}Cu{sub 3}O{sub 7} specimens made of melt-quench process produced the largest magnetic forces obtained in the laboratory so far. Models predicting the magnetic forces between superconductors and externally applied magnetic fields were studied. A numerical scheme based on the magnetization model was developed. The calculated levitation force-gap relationships showed a reasonable agreement with experimental results.

  6. The dual action gas thrust bearing - A new high load bearing concept

    NASA Technical Reports Server (NTRS)

    Etsion, I.

    1976-01-01

    The principle of utilizing hydrodynamic effects in diverging films for improving load capacity in gas thrust bearings is discussed. A new concept of dual action bearing based on that principle is described and analyzed. The potential of the new bearing is demonstrated both analytically for an infinitely long slider and by numerical solution for a flat sector shaped thrust bearing. It is shown that the dual action bearing can extend substantially the range of load carrying capacity in gas lubricated thrust bearings and improve their efficiency.

  7. Two High-Temperature Foil Journal Bearings

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    2006-01-01

    An enlarged, high-temperature-compliant foil bearing has been built and tested to demonstrate the feasibility of such bearings for use in aircraft gas turbine engines. Foil bearings are attractive for use in some machines in which (1) speeds of rotation, temperatures, or both exceed maximum allowable values for rolling-element bearings; (2) conventional lubricants decompose at high operating temperatures; and/or (3) it is necessary or desirable not to rely on conventional lubrication systems. In a foil bearing, the lubricant is the working fluid (e.g., air or a mixture of combustion gases) in the space between the journal and the shaft in the machine in which the bearing is installed.

  8. Magnetic bearings - State of the art

    NASA Astrophysics Data System (ADS)

    Fleming, David P.

    Magnetic bearings have existed for many years, at least in theory. Earnshaw's theorem, formulated in 1842, concerns stability of magnetic suspensions, and states that not all axes of a bearing can be stable without some means of active control. In Beam's widely referenced experiments, a tiny (1/64 in diameter) rotor was rotated to the astonishing speed of 800,000 rps while it was suspended in a magnetic field. Despite a long history, magnetic bearings have only begun to see practical application since about 1980. The development that finally made magnetic bearings practical was solid state electronics, enabling power supplies and controls to be reduced in size to where they are now comparable in volume to the bearings themselves. An attempt is made to document the current (1991) state of the art of magnetic bearings. The referenced papers are large drawn from two conferences publications published in 1988 and 1990 respectively.

  9. Effects of climate change on polar bears.

    PubMed

    Wiig, Øystein; Aars, Jon; Born, Erik W

    2008-01-01

    In this article, we review the effects on polar bears of global warming that have already been observed, and try to evaluate what may happen to the polar bears in the future. Many researchers have predicted a wide range of impacts of climate change on polar bear demography and conditions. A predicted major reduction in sea ice habitat will reduce the availability of ice associated seals, the main prey of polar bears, and a loss and fragmentation of polar bear habitat will ultimately lead to large future reductions in most subpopulations. It is likely that polar bears will be lost from many areas where they are common today and also that the total population will change into a few more distinctly isolated populations.

  10. Magnetic bearings-state of the art

    NASA Technical Reports Server (NTRS)

    Fleming, David P.

    1991-01-01

    Magnetic bearings have existed for many years, at least in theory. Earnshaw's theorem, formulated in 1842, concerns stability of magnetic suspensions, and states that not all axes of a bearing can be stable without some means of active control. In Beam's widely referenced experiments, a tiny (1/64 in diameter) rotor was rotated to the astonishing speed of 800,000 rps while it was suspended in a magnetic field. Despite a long history, magnetic bearings have only begun to see practical application since about 1980. The development that finally made magnetic bearings practical was solid state electronics, enabling power supplies and controls to be reduced in size to where they are now comparable in volume to the bearings themselves. An attempt is made to document the current (1991) state of the art of magnetic bearings. The referenced papers are large drawn from two conferences publications published in 1988 and 1990 respectively.

  11. Magnetic bearings - State of the art

    NASA Technical Reports Server (NTRS)

    Fleming, David P.

    1993-01-01

    Magnetic bearings have existed for many years, at least in theory. Earnshaw's theorem, formulated in 1842, concerns stability of magnetic suspensions, and states that not all axes of a bearing can be stable without some means of active control. In Beam's widely referenced experiments, a tiny (1/64 in diameter) rotor was rotated to the astonishing speed of 800,000 rps while it was suspended in a magnetic field. Despite a long history, magnetic bearings have only begun to see practical application since about 1980. The development that finally made magnetic bearings practical was solid state electronics, enabling power supplies and controls to be reduced in size to where they are now comparable in volume to the bearings themselves. An attempt is made to document the current (1991) state of the art of magnetic bearings. The referenced papers are large drawn from two conferences publications published in 1988 and 1990 respectively.

  12. Cryogenic Fluid Film Bearing Tester Development Study

    NASA Technical Reports Server (NTRS)

    Scharrer, Joseph K. (Editor); Murphy, Brian T.; Hawkins, Lawrence A.

    1993-01-01

    Conceptual designs were developed for the determination of rotordynamic coefficients of cryogenic fluid film bearings. The designs encompassed the use of magnetic and conventional excitation sources as well as the use of magnetic bearings as support bearings. Test article configurations reviewed included overhung, floating housing, and fixed housing. Uncertainty and forced response analyses were performed to assess quality of data and suitability of each for testing a variety of fluid film bearing designs. Development cost and schedule estimates were developed for each design. Facility requirements were reviewed and compared with existing MSFC capability. The recommended configuration consisted of a fixed test article housing centrally located between two magnetic bearings. The magnetic bearings would also serve as the excitation source.

  13. Cantilever mounted resilient pad gas bearing

    NASA Technical Reports Server (NTRS)

    Etsion, I. (Inventor)

    1978-01-01

    A gas-lubricated bearing is described, employing at least one pad mounted on a rectangular cantilever beam to produce a lubricating wedge between the face of the pad and a moving surface. The load-carrying and stiffness characteristics of the pad are related to the dimensions and modulus of elasticity of the beam. The bearing is applicable to a wide variety of types of hydrodynamic bearings.

  14. A miniature tilting pad gas lubricated bearing

    NASA Technical Reports Server (NTRS)

    Sixsmith, H.; Swift, W. L.

    1983-01-01

    This paper describes the design and development of a miniature tilting pad gas bearing developed for use in very small turbomachines. The bearings have been developed for cryogenic turboexpanders with shaft diameters down to about 0.3 cm and rotational speeds up to one million rpm. Cryogenic expansion turbines incorporating this type of bearing should be suitable for refrigeration rates down to about 10 w.

  15. Teflon lubrication of liquid oxygen turbopump bearings

    NASA Technical Reports Server (NTRS)

    Naerheim, Y.; Stocker, P. J.

    1989-01-01

    Ball bearings with glass fiber reinforced Teflon ball retainers from hot-fired liquid oxygen turbopumps were analyzed by X-ray photoelectron spectroscopy to determine the extent of Teflon transfer and/or chemical reaction at the bearing surface. No Teflon, but metal fluorides could be found on the metal surface. This indicates that Teflon decomposes and reacts with the bearing steel to form fluorides. Hence, Teflon does not appear to function directly as a lubricant under these operating conditions.

  16. Powder-Metallurgical Bearings For Turbopumps

    NASA Technical Reports Server (NTRS)

    Bhat, B. N.; Humphries, T. S.; Thom, R. L.; Moxson, V.; Friedman, G. I.; Dolan, F. J.; Shipley, R. J.

    1993-01-01

    Bearings fabricated by powder metallurgy developed for use in machines subjected to extremes of temperature, rolling-contact cyclic stresses, and oxidizing or otherwise corrosive fluids. Bearings also extend operating lives of other machines in which bearings required to resist extreme thermal, mechanical, and chemical stresses. One alloy exhibiting outstanding properties was MRC-2001. Resistance to fatigue, stress corrosion cracking, and wear found superior to that of 440C stainless steel.

  17. Thermal Interactions in Rolling Bearing Dynamics

    DTIC Science & Technology

    2002-03-01

    enhancements to ADORE, include, renewed code structure conforming to the FORTRAN-90 standard, refinement of ball bearing equilibrium module to include...implemented in the bearing dynamics com- puter code, ADORE. In addition to the model enhancements, the code is basically rewritten to conform to the FORTRAN-90...NOTES This is a Small Business 14. ABSTRACT Numerical enhancement Elements (ADORE), ha variation in bearing elem heat generation consider Averaging

  18. Silicon Nitride Hybrid Bearing Fatigue Life Comparisons

    DTIC Science & Technology

    2007-11-02

    by Lundberg and Palmgren (4,5) to present their analytical models for rolling element bearing fatigue life. Consequently, their use of the Weibull... bearing fatigue life, and establishing design levels. Lundberg and Palmgren utilize power law assumptions for the variates of load (stress) and for life...Mechanisms Symposium, NASA/CP-1998-207191, pp 237-251, May 13-18, 1998. 4. Lunberg,, G. and Palmgren , A., "Dynamic Capacity of Rolling Bearings

  19. Lung cancer in women

    PubMed Central

    Barrera-Rodriguez, Raúl; Morales-Fuentes, Jorge

    2012-01-01

    Recent biological advances in tumor research provide clear evidence that lung cancer in females is different from that in males. These differences appear to have a direct impact on the clinical presentation, histology, and outcomes of lung cancer. Women are more likely to present with lung adenocarcinoma, tend to receive a diagnosis at an earlier age, and are more likely to be diagnosed with localized disease. Women may also be more predisposed to molecular aberrations resulting from the carcinogenic effects of tobacco, but do not appear to be more susceptible than men to developing lung cancer. The gender differences found in female lung cancer make it mandatory that gender stratification is used in clinical trials in order to improve the survival rates of patients with lung cancer. PMID:28210127

  20. Effect of Rolling Bearing Refurbishment and Restoration on Bearing Life and Reliability

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.; Branzai, Emanuel V.

    2005-01-01

    For nearly four decades it has been a practice in commercial and military aircraft application that rolling-element bearings removed at maintenance or overhaul be reworked and returned to service. The work presented extends previously reported bearing life analysis to consider the depth (Z(45)) to maximum shear stress (45) on stressed volume removal and the effect of replacing the rolling elements with a new set. A simple algebraic relationship was established to determine the L(10) life of bearing races subject to bearing rework. Depending on the extent of rework and based upon theoretical analysis, representative life factors (LF) for bearings subject to rework ranged from 0.87 to 0.99 the lives of new bearings. Based on bearing endurance data, 92 percent of the bearing sets that would be subject to rework would result in L(10) lives equaling and/or exceeding that predicted for new bearings with the remaining 8 percent having the potential to achieve the analytically predicted life of new bearings when one of the rings is replaced at rework.. The potential savings from bearing rework varies from 53 to 82 percent that of new bearings depending on the cost, size and complexity of the bearing.

  1. Permanent Magnetic Bearing for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Morales, Winfredo; Fusaro, Robert; Kascak, Albert

    2008-01-01

    A permanent, totally passive magnetic bearing rig was designed, constructed, and tested. The suspension of the rotor was provided by two sets of radial permanent magnetic bearings operating in the repulsive mode. The axial support was provided by jewel bearings on both ends of the rotor. The rig was successfully operated to speeds of 5500 rpm using an air impeller. Radial and axial stiffnesses of the permanent magnetic bearings were experimentally measured and then compared to finite element results. The natural damping of the rotor was measured and a damping coefficient was calculated.

  2. Technical Development Path for Gas Foil Bearings

    NASA Technical Reports Server (NTRS)

    Dellacorte, Christopher

    2016-01-01

    Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet to be realized. This paper investigates the key technological developments that have characterized foil bearing advances. It is expected that a better understanding of foil gas bearing development path will aid in future development and progress towards more advanced applications.

  3. A spherical gas bearing for airborne application

    NASA Technical Reports Server (NTRS)

    Bouvier, A.; Schmertz, J. C.

    1974-01-01

    A spherical gas bearing is analyzed and tested for an airborne application. The externally pressurized bearing supports an inertially stabilized 36-in aperture, infrared telescope. The bearing provides the isolation of rotary motion from the aircraft and also serves as a seal between the aircraft cabin and cavity condition at 50,000 ft altitude. The accompanying temperature gradient of 135 F across the 16-in.-diam bearing created special design and manufacturing considerations. Test data on the static load under temperature and vacuum environment are presented in support of the analysis.

  4. Surficial deposits in the Bear Lake Basin

    USGS Publications Warehouse

    Reheis, Marith C.; Laabs, Benjamin J.C.; Forester, Richard M.; McGeehin, John P.; Kaufman, Darrell S.; Bright, Jordon

    2005-01-01

    Mapping and dating of surficial deposits in the Bear Lake drainage basin were undertaken to provide a geologic context for interpretation of cores taken from deposits beneath Bear Lake, which sometimes receives water and sediment from the glaciated Bear River and sometimes only from the small drainage basin of Bear Lake itself. Analyses of core sediments by others are directed at (1) constructing a high-resolution climate record for the Bear Lake area during the late Pleistocene and Holocene, and (2) investigating the sources and weathering history of sediments in the drainage basin. Surficial deposits in the upper Bear River and Bear Lake drainage basins are different in their overall compositions, although they do overlap. In the upper Bear River drainage, Quaternary deposits derived from glaciation of the Uinta Range contain abundant detritus weathered from Precambrian quartzite, whereas unglaciated tributaries downstream mainly contribute finer sediment weathered from much younger, more friable sedimentary rocks. In contrast, carbonate rocks capped by a carapace of Tertiary sediments dominate the Bear Lake drainage basin.

  5. Fractional Whirl Motion in Wave Journal Bearings

    NASA Technical Reports Server (NTRS)

    Dimofte, Florin; Hendricks, Robert C.

    1996-01-01

    Unloaded gas, plain journal bearings experience sub-synchronous whirl motion due to fluid film instabilities and wall contact usually occurs immediately after the onset of the whirl motion. An alternative is the wave journal bearing which significantly improves bearing stability. The predicted threshold where the sub-synchronous whirl motion starts was well confirmed by the experimental observation. In addition, both a two-wave and a three-wave journal bearing can operate free of sub-synchronous whirl motion over a large range in speeds. When the sub-synchronous whirl motion occurs, both the two-wave and three-wave bearing can run in a whirl orbit well within the bearing clearance. At large clearances and wave amplitudes a two-wave bearing, unliKe other bearings, can exhibit a sub-synchronous whirl movement at both low and high speeds, but can run extremely stable and without whirl at intermediate speeds. Moreover, in these cases, the whirl frequencies are close to a quarter of the synchronous speed. The three-wave bearing can exhibit sub-synchronous whirl motion only after a specific threshold when the speed increases and the whirl frequencies are close to half of the synchronous speed.

  6. Superconducting bearings with levitation control configurations

    SciTech Connect

    Flom, Y.; Royston, J.D.

    1992-05-26

    This patent describes a superconducting rotating assembly. It comprises first and second bearing means comprising a material exhibiting superconducting properties; a rotatable member having two extremities aligned along a common axis; magnet means at each extremity; means for maintaining each the bearing means at a temperature where the superconducting properties are manifest; means for rotating the rotatable member; means for sensing the position of the rotatable member relative to each the bearing means; and means for controlling the levitation forces exerted on the rotatable member by each the bearing means.

  7. Development of passive superconducting bearings. Phase 3

    NASA Astrophysics Data System (ADS)

    Rao, Dantam K.

    1993-05-01

    This report documents the development of a passive superconducting bearing that is used to levitate relatively heavy rotors. This bearing was used to levitate a 7 lb rotor and spin at speeds of up to 12,000 rpm. The success of this effort indicates that the superconducting bearings have the potential for transition from a mere laboratory curiosity to a functional bearing component in a wider range of practical applications such as cryoturbopumps, miniature cryocoolers, and magnetic refrigerators. In addition, several configurations using superconductors to support loads along a single axis were investigated. The effort was directed to identify a specific configuration that offers a very high stiffness.

  8. The asymmetrically stepped, orifice compensated hydrostatic bearing

    NASA Astrophysics Data System (ADS)

    Scharrer, J. K.; Hibbs, R. I.; San Andres, L.

    1992-07-01

    An improved hydrostatic bedaring configuration consisting of a conventional orifice compensated, continuous, hydrostatic bearing augmented on one side by a ring with a smaller radial clearance is presented. Results for the leakage and rotordynamic coeffcients of this asymmetrically stepped hydrostatic bearing are calculated using a numerical solution of the film-average Navier-Stokes equations. Results of a parametric study on the effects of ring geometry and recess position on hydrostatic bearing performance are presented. The results show that the presence of the asymmetric step enhances the rotordynamic performance of an orifice compensated hydrostatic bearing.

  9. Technical Development Path for Foil Gas Bearings

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher

    2008-01-01

    Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet to be realized. This paper investigates the key technological developments that have characterized foil bearing advances. It is expected that a better understanding of foil gas bearing development path will aid in future development and progress towards more advanced applications.

  10. Fractional Whirl Motion in Wave Journal Bearings

    NASA Technical Reports Server (NTRS)

    Dimofte, Florin; Hendricks, Robert C.

    1996-01-01

    Unloaded gas, plain journal bearings experience sub-synchronous whirl motion due to fluid film instabilities and wall contact usually occurs immediately after the onset of the whirl motion. An alternative is the wave journal bearing which significantly improves bearing stability. The predicted threshold where the sub-synchronous whirl motion starts was well confirmed by the experimental observation. In addition, both a two-wave and a three-wave journal bearing can operate free of sub-synchronous whirl motion over a large range in speeds. When the sub-synchronous whirl motion occurs, both the two-wave and three-wave bearing can run in a whirl orbit well within the bearing clearance. At large clearances and wave amplitudes a two-wave bearing, unliKe other bearings, can exhibit a sub-synchronous whirl movement at both low and high speeds, but can run extremely stable and without whirl at intermediate speeds. Moreover, in these cases, the whirl frequencies are close to a quarter of the synchronous speed. The three-wave bearing can exhibit sub-synchronous whirl motion only after a specific threshold when the speed increases and the whirl frequencies are close to half of the synchronous speed.

  11. Cylindrical roller bearings with profiled contacting surfaces

    NASA Astrophysics Data System (ADS)

    Creţu, S. S.

    2017-02-01

    An initial loading of cylindrical roller bearings in the elastic-plastic domain was performed to induce elastic shakedown phenomena able to change the basic profiles of both, rollers and raceways, which endorses a different value for the basic reference rating life. Fatigue life tests carried out on four lots of NJ206 cylindrical roller bearings revealed much higher values of L10 and Lm criteria for the bearings lots which experienced a suitable initial loading operation in the elastic-plastic domain. The reference rating lives, evaluated by using the lamina technique, confirmed the superiority of bearings lots which undergone an appropriate primary loading in the elastic-plastic domain.

  12. Gearbox Reliability Collaborative Bearing Calibration

    SciTech Connect

    van Dam, J.

    2011-10-01

    NREL has initiated the Gearbox Reliability Collaborative (GRC) to investigate the root cause of the low wind turbine gearbox reliability. The GRC follows a multi-pronged approach based on a collaborative of manufacturers, owners, researchers and consultants. The project combines analysis, field testing, dynamometer testing, condition monitoring, and the development and population of a gearbox failure database. At the core of the project are two 750kW gearboxes that have been redesigned and rebuilt so that they are representative of the multi-megawatt gearbox topology currently used in the industry. These gearboxes are heavily instrumented and are tested in the field and on the dynamometer. This report discusses the bearing calibrations of the gearboxes.

  13. Movements of Yellowstone grizzly bears

    USGS Publications Warehouse

    Blanchard, Bonnie M.; Knight, Richard R.

    1991-01-01

    Ninety-seven grizzly bears Ursus arctos horribilis were radio-located 6299 times during 1975–1987. Annual range sizes differed by sex, age, reproductive status and amount of precipitation. Females exhibited greater fidelity to seasonal and annual ranges than males. Weaned female offspring generally remained in the vicinity of the maternal range, while weaned males often made substantial movements to unexplored country. Average total home range size was 884 km2 for females and 3757 km2 for males. Males consistently exhibited greater indices of movement and range sizes than females. All cohorts had larger mean ranges during this study than during the period 1959–1969 when the population had access to open garbage dumps. Movements and elevational distribution of all cohorts were related to availability of whitebark pine Pinus albicaulis seeds. We hypothesized that females with cubs-of-the-year and yearlings were displaced from most productive habitats during seasons and years of limited food availability.

  14. Bringing energy savings to bear.

    PubMed

    Waugh, Harry

    2011-05-01

    Harry Waugh, the Scottish branch member of IHEEM's Council, and a former Health Facilities Scotland energy manager, who now runs his own energy/carbon consultancy, "Call Harry", argues that growing reliance on technology will continue to strengthen the need for effective energy management in the healthcare sphere. In an article that first appeared in the 2010 IFHE Digest, he looks back at previous Government and NHS energy-saving initiatives, and describes a recent Scottish carbon reduction campaign, aimed at health service staff, which used the plight of an imaginary character, Floe Bear, cut off from his natural habitat by melting ice floes, to bring humour to a serious subject and encourage buy-in in from staff.

  15. Pediatric Lung Transplantation.

    PubMed

    Sweet, Stuart C

    2017-06-01

    Pediatric lung transplant is a viable option for treatment of end-stage lung disease in children, with > 100 pediatric lung transplants reported to the Registry of the International Society of Heart and Lung Transplantation each year. Long-term success is limited by availability of donor organs, debilitation as a result of chronic disease, impaired mucus clearance resulting from both surgical and pharmacologic interventions, increased risk for infection resulting from immunosuppression, and most importantly late complications, such as chronic lung allograft dysfunction. Opportunities for investigation and innovation remain in all of these domains: (1) Ex vivo lung perfusion is a promising technology with the potential for increasing the lung donor pool, (2) evolving extracorporeal support strategies coupled with effective rehabilitation will effectively bridge critically ill patients to transplant, and most importantly, (3) research efforts intended to increase our understanding of the underlying mechanisms of chronic lung allograft dysfunction will ultimately lead to the development of effective therapies to prevent or treat the variety of chronic lung allograft dysfunction presentations. Copyright © 2017 by Daedalus Enterprises.

  16. Experimental Evaluation of Journal Bearing Stability and New Gas Bearing Material

    NASA Technical Reports Server (NTRS)

    Keith, Theo G., Jr.; Dimofte, Florin

    2001-01-01

    It has been estimated that the noise levels in aircraft engine transmissions can be reduced by as much as 10 dB through the use of journal bearings. The potential benefits of lower noise levels include reduced wear, longer gear life and enhanced comfort for passengers and crew. Based on this concept the journal-thrust wave bearing was analyzed and its performance was evaluated. Numerical codes, developed over the past 30 years by Dr. Dimofte, were used to predict the performance of the bearing. The wave bearing is a fluid film bearing and therefore was analyzed using the Reynolds pressure equation. The formulation includes turbulent flow concepts and possesses a viscosity-temperature correction. The centrifugal growth of the bearing diameter and the deformation of the bearing under gear loads were also incorporated into the code. An experimental rig was developed to test the journal-thrust wave bearing.

  17. Dynamic modelling and response characteristics of a magnetic bearing rotor system with auxiliary bearings

    NASA Technical Reports Server (NTRS)

    Free, April M.; Flowers, George T.; Trent, Victor S.

    1995-01-01

    Auxiliary bearings are a critical feature of any magnetic bearing system. They protect the soft iron core of the magnetic bearing during an overload or failure. An auxiliary bearing typically consists of a rolling element bearing or bushing with a clearance gap between the rotor and the inner race of the support. The dynamics of such systems can be quite complex. It is desired to develop a rotordynamic model which describes the dynamic behavior of a flexible rotor system with magnetic bearings including auxiliary bearings. The model is based upon an experimental test facility. Some simulation studies are presented to illustrate the behavior of the model. In particular, the effects of introducing sideloading from the magnetic bearing when one coil fails is studied.

  18. Oil exchange between ball bearings and cotton-phenolic ball-bearing retainers

    NASA Astrophysics Data System (ADS)

    Bertrand, P. A.; Carre, D. J.; Bauer, R.

    1994-09-01

    Experiments have been performed that determine for the first time the transfer of oil between cotton-phenolic ball-bearing retainers and operating ball bearings. A full retainer exchanges oil with the metal parts of the bearing, probably by diffusional mixing. There is no net delivery of oil from the retainer to the metal parts of the bearing. A partially filled retainer (such as one that has been incompletely impregnated) absorbs oil from the bearing even during operation, thus drying the bearing. A fully-impregnated retainer does not deliver any significant amount of additional oil to the metal parts of a poorly lubricated bearing. The retainer will not prevent lubricant degradation and premature bearing failure under the conditions of these experiments.

  19. Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage.

    PubMed

    Hailer, Frank; Kutschera, Verena E; Hallström, Björn M; Klassert, Denise; Fain, Steven R; Leonard, Jennifer A; Arnason, Ulfur; Janke, Axel

    2012-04-20

    Recent studies have shown that the polar bear matriline (mitochondrial DNA) evolved from a brown bear lineage since the late Pleistocene, potentially indicating rapid speciation and adaption to arctic conditions. Here, we present a high-resolution data set from multiple independent loci across the nuclear genomes of a broad sample of polar, brown, and black bears. Bayesian coalescent analyses place polar bears outside the brown bear clade and date the divergence much earlier, in the middle Pleistocene, about 600 (338 to 934) thousand years ago. This provides more time for polar bear evolution and confirms previous suggestions that polar bears carry introgressed brown bear mitochondrial DNA due to past hybridization. Our results highlight that multilocus genomic analyses are crucial for an accurate understanding of evolutionary history.

  20. Dynamic modelling and response characteristics of a magnetic bearing rotor system including auxiliary bearings

    NASA Technical Reports Server (NTRS)

    Free, April M.; Flowers, George T.; Trent, Victor S.

    1993-01-01

    Auxiliary bearings are a critical feature of any magnetic bearing system. They protect the soft iron core of the magnetic bearing during an overload or failure. An auxiliary bearing typically consists of a rolling element bearing or bushing with a clearance gap between the rotor and the inner race of the support. The dynamics of such systems can be quite complex. It is desired to develop a rotor-dynamic model and assess the dynamic behavior of a magnetic bearing rotor system which includes the effects of auxiliary bearings. Of particular interest is the effects of introducing sideloading into such a system during failure of the magnetic bearing. A model is developed from an experimental test facility and a number of simulation studies are performed. These results are presented and discussed.

  1. Rotor-Bearing Dynamics Technology Design Guide. Part 4. Cylindrical Roller Bearings

    DTIC Science & Technology

    1979-12-01

    ýbluck ,,lb.,mb i Tapered Roller Bearings Roller Beating Stiffness Tapered Roller Bearing Stiffness Turbine Bearings VRoller Bearings Rotordynamics ...input for rotordynamic response programs. The complete stiffness matrix is calculated including centrifugal effects. Considerations such as elastohydro...those parts directly connected with preparation of input for the rotordynamic response programs (Part 1(5) of the revised series) were retained. The

  2. Evaluation of bearing configurations using the single bearing tester in liquid nitrogen

    NASA Technical Reports Server (NTRS)

    Jett, T.; Hall, P.; Thom, R.

    1991-01-01

    Various bearing configurations were tested using the Marshall Space Flight Center single bearing tester with LN2 as the cryogenic coolant. The baseline was one Rocketdyne phase one high pressure oxidizer turbopump (HPOTP) pump end 45-mm bore bearing. The bearing configurations that were tested included a Salox/M cage configuration, a silicon nitride ball configuration, an elongated cage configuration, and a Bray 601 grease configuration.

  3. Your Lungs and Respiratory System

    MedlinePlus

    ... Lifesaver Kids Talk About: Coaches Your Lungs & Respiratory System KidsHealth > For Kids > Your Lungs & Respiratory System Print ... its regular size. You've just felt the power of your lungs! continue A Look Inside the ...

  4. 6 Common Cancers - Lung Cancer

    MedlinePlus

    ... Home Current Issue Past Issues 6 Common Cancers - Lung Cancer Past Issues / Spring 2007 Table of Contents ... for Desperate Housewives. (Photo ©2005 Kathy Hutchins / Hutchins) Lung Cancer Lung cancer causes more deaths than the ...

  5. Genetics Home Reference: lung cancer

    MedlinePlus

    ... Me Understand Genetics Home Health Conditions lung cancer lung cancer Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Lung cancer is a disease in which certain cells ...

  6. Interstitial lung disease - adults - discharge

    MedlinePlus

    ... lung disease Pulmonary alveolar proteinosis Rheumatoid lung disease Sarcoidosis Patient Instructions Eating extra calories when sick - adults ... team. Related MedlinePlus Health Topics Interstitial Lung Diseases Sarcoidosis Browse the Encyclopedia A.D.A.M., Inc. ...

  7. Phylogeography of mitochondrial DNA variation in brown bears and polar bears

    USGS Publications Warehouse

    Shields, Gerald F.; Adams, Deborah; Garner, Gerald W.; Labelle, Martine; Pietsch, Jacy; Ramsay, Malcolm; Schwartz, Charles; Titus, Kimberly; Williamson, Scott

    2000-01-01

    We analyzed 286 nucleotides of the middle portion of the mitochondrial cytochrome b gene of 61 brown bears from three locations in Alaska and 55 polar bears from Arctic Canada and Arctic Siberia to test our earlier observations of paraphyly between polar bears and brown bears as well as to test the extreme uniqueness of mitochondrial DNA types of brown bears on Admiralty, Baranof, and Chichagof (ABC) islands of southeastern Alaska. We also investigated the phylogeography of brown bears of Alaska's Kenai Peninsula in relation to other Alaskan brown bears because the former are being threatened by increased human development. We predicted that: (1) mtDNA paraphyly between brown bears and polar bears would be upheld, (2) the mtDNA uniqueness of brown bears of the ABC islands would be upheld, and (3) brown bears of the Kenai Peninsula would belong to either clade II or clade III of brown bears of our earlier studies of mtDNA. All of our predictions were upheld through the analysis of these additional samples.

  8. Phylogeography of mitochondrial DNA variation in brown bears and polar bears.

    PubMed

    Shields, G F; Adams, D; Garner, G; Labelle, M; Pietsch, J; Ramsay, M; Schwartz, C; Titus, K; Williamson, S

    2000-05-01

    We analyzed 286 nucleotides of the middle portion of the mitochondrial cytochrome b gene of 61 brown bears from three locations in Alaska and 55 polar bears from Arctic Canada and Arctic Siberia to test our earlier observations of paraphyly between polar bears and brown bears as well as to test the extreme uniqueness of mitochondrial DNA types of brown bears on Admiralty, Baranof, and Chichagof (ABC) islands of southeastern Alaska. We also investigated the phylogeography of brown bears of Alaska's Kenai Peninsula in relation to other Alaskan brown bears because the former are being threatened by increased human development. We predicted that: (1) mtDNA paraphyly between brown bears and polar bears would be upheld, (2) the mtDNA uniqueness of brown bears of the ABC islands would be upheld, and (3) brown bears of the Kenai Peninsula would belong to either clade II or clade III of brown bears of our earlier studies of mtDNA. All of our predictions were upheld through the analysis of these additional samples. Copyright 2000 Academic Press.

  9. Unbalance Response Prediction for Rotors on Ball Bearings Using Speed and Load Dependent Nonlinear Bearing Stiffness

    NASA Technical Reports Server (NTRS)

    Fleming, David P.; Poplawski, J. V.

    2003-01-01

    Rolling-element bearing forces vary nonlinearly with bearing deflection. Thus an accurate rotordynamic analysis requires that bearing forces corresponding to the actual bearing deflection be utilized. For this work bearing forces were calculated by COBRA-AHS, a recently developed rolling-element bearing analysis code. Bearing stiffness was found to be a strong function of bearing deflection, with higher deflection producing markedly higher stiffness. Curves fitted to the bearing data for a range of speeds and loads were supplied to a flexible rotor unbalance response analysis. The rotordynamic analysis showed that vibration response varied nonlinearly with the amount of rotor imbalance. Moreover, the increase in stiffness as critical speeds were approached caused a large increase in rotor and bearing vibration amplitude over part of the speed range compared to the case of constant bearing stiffness. Regions of bistable operation were possible, in which the amplitude at a given speed was much larger during rotor acceleration than during deceleration. A moderate amount of damping will eliminate the bistable region, but this damping is not inherent in ball bearings.

  10. State Space Formulation of Nonlinear Vibration Responses Collected from a Dynamic Rotor-Bearing System: An Extension of Bearing Diagnostics to Bearing Prognostics.

    PubMed

    Tse, Peter W; Wang, Dong

    2017-02-14

    Bearings are widely used in various industries to support rotating shafts. Their failures accelerate failures of other adjacent components and may cause unexpected machine breakdowns. In recent years, nonlinear vibration responses collected from a dynamic rotor-bearing system have been widely analyzed for bearing diagnostics. Numerous methods have been proposed to identify different bearing faults. However, these methods are unable to predict the future health conditions of bearings. To extend bearing diagnostics to bearing prognostics, this paper reports the design of a state space formulation of nonlinear vibration responses collected from a dynamic rotor-bearing system in order to intelligently predict bearing remaining useful life (RUL). Firstly, analyses of nonlinear vibration responses were conducted to construct a bearing health indicator (BHI) so as to assess the current bearing health condition. Secondly, a state space model of the BHI was developed to mathematically track the health evolution of the BHI. Thirdly, unscented particle filtering was used to predict bearing RUL. Lastly, a new bearing acceleration life testing setup was designed to collect natural bearing degradation data, which were used to validate the effectiveness of the proposed bearing prognostic method. Results show that the prediction accuracy of the proposed bearing prognostic method is promising and the proposed bearing prognostic method is able to reflect future bearing health conditions.

  11. State Space Formulation of Nonlinear Vibration Responses Collected from a Dynamic Rotor-Bearing System: An Extension of Bearing Diagnostics to Bearing Prognostics

    PubMed Central

    Tse, Peter W.; Wang, Dong

    2017-01-01

    Bearings are widely used in various industries to support rotating shafts. Their failures accelerate failures of other adjacent components and may cause unexpected machine breakdowns. In recent years, nonlinear vibration responses collected from a dynamic rotor-bearing system have been widely analyzed for bearing diagnostics. Numerous methods have been proposed to identify different bearing faults. However, these methods are unable to predict the future health conditions of bearings. To extend bearing diagnostics to bearing prognostics, this paper reports the design of a state space formulation of nonlinear vibration responses collected from a dynamic rotor-bearing system in order to intelligently predict bearing remaining useful life (RUL). Firstly, analyses of nonlinear vibration responses were conducted to construct a bearing health indicator (BHI) so as to assess the current bearing health condition. Secondly, a state space model of the BHI was developed to mathematically track the health evolution of the BHI. Thirdly, unscented particle filtering was used to predict bearing RUL. Lastly, a new bearing acceleration life testing setup was designed to collect natural bearing degradation data, which were used to validate the effectiveness of the proposed bearing prognostic method. Results show that the prediction accuracy of the proposed bearing prognostic method is promising and the proposed bearing prognostic method is able to reflect future bearing health conditions. PMID:28216586

  12. Lung protective strategies in anaesthesia.

    PubMed

    Kilpatrick, B; Slinger, P

    2010-12-01

    Patients are at risk for several types of lung injury in the perioperative period including atelectasis, pneumonia, pneumothorax, acute lung injury, and acute respiratory distress syndrome. Anaesthetic management can cause, exacerbate, or ameliorate these injuries. This review examines the effects of perioperative mechanical ventilation and its role in ventilator-induced lung injury. Lung protective ventilatory strategies to specific clinical situations such as cardiopulmonary bypass and one-lung ventilation along with newer novel lung protective strategies are discussed.

  13. Lubrication of rolling-element bearings

    NASA Technical Reports Server (NTRS)

    Parker, R. J.

    1980-01-01

    The lubrication of rolling element bearings is surveyed. Emphasis is on the critical design aspects related to speed, temperature, and ambient pressure environment. Types of lubrication including grease, jets, mist, wick, and through the race are discussed. The historical development, present state of technology, and the future problems of rolling element bearing lubrication are discussed.

  14. Anatomy of a bearing torque problem

    NASA Technical Reports Server (NTRS)

    Phinney, Damon D.

    1987-01-01

    In the early 1970s, an antenna despin drive was developed for MBB solar science satellite HELIOS. A problem with high bearing drag torque that was encountered on the two flight models of this drive, after successful tests were completed on twelve bearings, an engineering model, and the qualification unit is discussed.

  15. Air-Bearing Table for Machine Shops

    NASA Technical Reports Server (NTRS)

    Ambrisco, D.

    1986-01-01

    Frequent workpiece repositioning made easier. Air-bearing table facilitates movement of heavy workpiece during machining or between repeated operations at different positions. Table assembly consists of workpiece supporting fixture riding on air bearing. Table especially useful for inertia welding, in which ease of mobility is important.

  16. Damage Mechanics Approach for Bearing Lifetime Prognostics

    NASA Astrophysics Data System (ADS)

    Qiu, Jing; Seth, Brij B.; Liang, Steven Y.; Zhang, Cheng

    2002-09-01

    The ability to achieve accurate bearing prognostics is critical to the optimal maintenance of rotating machinery in the interest of cost and productivity. However, techniques to real time predict the lifetime of a bearing under practical operating conditions have not been well developed. In this paper, a stiffness-based prognostic model for bearing systems based on vibration response analysis and damage mechanics is discussed. As the bearing system is considered as a single-degree-of-freedom vibratory system, its natural frequency and its acceleration amplitude at the natural frequency can be related to the system stiffness. On the other hand, the relationship between failure lifetime, running time and stiffness variation can be established from the damage mechanics. Combining the above two, the natural frequency and the acceleration amplitude of a bearing system can be related to its running time and failure lifetime. Thus, the failure lifetime of a bearing system can be predicted on-line based on vibration measurement. Experiments have been performed on a tapered roller bearing life testing stand under various operation conditions to calibrate and to validate the proposed model. The comparison between model-calculated data and experimental results indicates that this model can be used to effectively predict the failure lifetime and the remaining life of a bearing system.

  17. Methods and systems for micro bearings

    DOEpatents

    Stalford, Harold L.

    2012-10-09

    A micro drive assembly may comprise a substrate, a micro shall oriented in-plane with the substrate and at least one micro bearing to support rotation of the micro shaft. The micro shaft and micro bearing may be in or less than the micrometer domain.

  18. Precision instrumentation for rolling element bearing characterization

    SciTech Connect

    Marsh, Eric R.; Vigliano, Vincent C.; Weiss, Jeffrey R.; Moerlein, Alex W.; Vallance, R. Ryan

    2007-03-15

    This article describes an instrument to measure the error motion of rolling element bearings. This challenge is met by simultaneously satisfying four requirements. First, an axial preload must be applied to seat the rolling elements in the bearing races. Second, one of the races must spin under the influence of an applied torque. Third, rotation of the remaining race must be prevented in a way that leaves the radial, axial/face, and tilt displacements free to move. Finally, the bearing must be fixtured and measured without introducing off-axis loading or other distorting influences. In the design presented here, an air bearing reference spindle with error motion of less than 10 nm rotates the inner race of the bearing under test. Noninfluencing couplings are used to prevent rotation of the bearing outer race and apply an axial preload without distorting the bearing or influencing the measurement. Capacitive displacement sensors with 2 nm resolution target the nonrotating outer race. The error motion measurement repeatability is shown to be less than 25 nm. The article closes with a discussion of how the instrument may be used to gather data with sufficient resolution to accurately estimate the contact angle of deep groove ball bearings.

  19. Magnetic perturbation inspection of inner bearing races

    NASA Technical Reports Server (NTRS)

    Barton, J. R.; Lankford, J.

    1972-01-01

    Approximately 100 inner race bearings were inspected nondestructively prior to endurance testing. Two of the bearings which failed during testing spalled at the sites of subsurface inclusions previously detected by using magnetic field perturbation. At other sites initially judged to be suspect, subsurface inclusion-nucleated cracking was observed. Inspection records and metallurgical sectioning results are presented and discussed.

  20. Positive contact, self retaining bearing seals

    SciTech Connect

    Johnson, B.H.; Larsen, L.

    1992-05-05

    This patent describes a bearing. It comprises: an inner race; an outer race; bearing means engaged between the inner and outer races; means for sealing a space between the inner and outer races, a groove in one of the inner and outer races.

  1. Freon 21 bearing lubrication and coolant system

    NASA Technical Reports Server (NTRS)

    Bodensieck, E. J.; Gustafson, M. J.

    1972-01-01

    Lubrication and cooling of turbopump rotor bearings by liquid Freon 21 is reported. Freon expands in rotor bearing and acts as heat sink by removing heat during warming and evaporation. Gaseous Freon is removed by vacuum pump controlling rotor chamber operation.

  2. Electronic visualization of gas bearing behavior

    NASA Technical Reports Server (NTRS)

    Evans, R. C.; Klassen, H. A.; Wong, R. Y.

    1969-01-01

    Visualization technique produces a visual simulation of gas bearing operation by electronically combining the outputs from the clearance probes used to monitor bearing component motion. Computerized recordings of the probes output are processed, displayed on an oscilloscope screen and recorded with a high-speed motion picture camera.

  3. Stabilizing gas bearing in free piston machines

    NASA Technical Reports Server (NTRS)

    Dhar, Manmohan (Inventor)

    1992-01-01

    In a free piston engine, to reduce dynamic loads on the reciprocating elements caused by a time varying pressure gradient across the gas bearing and close clearance seals provided therein, drain galleries are incorporated at the ends of the gas bearings to isolate the same, and circumferentially spaced grooves are incorporated in the close clearance seal region.

  4. High temperature coatings for gas bearings

    NASA Technical Reports Server (NTRS)

    Murray, S. F.

    1969-01-01

    Aluminum oxide and nickel-chrome bonded chrome carbide coatings enhance the performance of gas bearings at temperatures up to 1400 degrees F. A plasma-sprayed aluminum-oxide coating is applied to the bearing surface and a plasma- sprayed 25 percent nickel-chrome bonded chrome carbide coating is applied to the journal surface.

  5. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draws of the Baltimore...

  6. Measuring Bearing Wear Via Weight Loss

    NASA Technical Reports Server (NTRS)

    Keba, John E.; Moore, Richard S.

    1989-01-01

    Wear in critical parts of bearings measured via amounts of weight lost during use. Technique applicable in general to bearings made of nonporous materials. Weight-loss measurements easier, faster, more precise, and less likely to damage measured parts. Weight-loss measurements performed in clean rooms and under constraint of extreme cleanliness for compatability with liquid oxygen.

  7. Friction coefficients of PTFE bearing liner

    NASA Technical Reports Server (NTRS)

    Daniels, C. M.

    1979-01-01

    Data discusses frictional characteristics of PTFE (polytetrafluoroethylene) under temperature extremes and in vacuum environment. Tests were also run on reduced scale hardware to determine effects of vacuum. Data is used as reference by designers of aircraft-control system rod-end bearings and for bearings used in polar regions.

  8. Self-adjusting magnetic bearing systems

    DOEpatents

    Post, R.F.

    1998-07-21

    A self-adjusting magnetic bearing automatically adjusts the parameters of an axially unstable magnetic bearing such that its force balance is maintained near the point of metastable equilibrium. Complete stabilization can be obtained with the application of weak restoring forces either from a mechanical bearing (running at near-zero load, thus with reduced wear) or from the action of residual eddy currents in a snubber bearing. In one embodiment, a torque is generated by the approach of a slotted pole to a conducting plate. The torque actuates an assembly which varies the position of a magnetic shunt to change the force exerted by the bearing. Another embodiment achieves axial stabilization by sensing vertical displacements in a suspended bearing element, and using this information in an electrical servo system. In a third embodiment, as a rotating eddy current exciter approaches a stationary bearing, it heats a thermostat which actuates an assembly to weaken the attractive force between the two bearing elements. An improved version of an electromechanical battery utilizing the designs of the various embodiments is described. 7 figs.

  9. Precision instrumentation for rolling element bearing characterization.

    PubMed

    Marsh, Eric R; Vigliano, Vincent C; Weiss, Jeffrey R; Moerlein, Alex W; Vallance, R Ryan

    2007-03-01

    This article describes an instrument to measure the error motion of rolling element bearings. This challenge is met by simultaneously satisfying four requirements. First, an axial preload must be applied to seat the rolling elements in the bearing races. Second, one of the races must spin under the influence of an applied torque. Third, rotation of the remaining race must be prevented in a way that leaves the radial, axial/face, and tilt displacements free to move. Finally, the bearing must be fixtured and measured without introducing off-axis loading or other distorting influences. In the design presented here, an air bearing reference spindle with error motion of less than 10 nm rotates the inner race of the bearing under test. Noninfluencing couplings are used to prevent rotation of the bearing outer race and apply an axial preload without distorting the bearing or influencing the measurement. Capacitive displacement sensors with 2 nm resolution target the nonrotating outer race. The error motion measurement repeatability is shown to be less than 25 nm. The article closes with a discussion of how the instrument may be used to gather data with sufficient resolution to accurately estimate the contact angle of deep groove ball bearings.

  10. Adjustable base for centering staked bearings

    NASA Technical Reports Server (NTRS)

    Berson, L. A.

    1980-01-01

    Adjustable base permits housing and race to be supported separately so that unequal widths can be accounted for and bearing staked on center. If race is centered and staked on flat base and housing and race are not same width, then offset may occur and bearing will be set off center.

  11. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  12. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  13. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  14. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draws of the...

  15. Pneumatic power is transmitted through air bearing

    NASA Technical Reports Server (NTRS)

    Johnson, H. I.; Wobig, O. A.

    1964-01-01

    A more efficient method for supplying high pressure air to an air bearing and pneumatic equipment mounted on it has been developed. The system uses a conventional air bearing and an air-supported sphere with a central passage. High pressure air is channeled through it into the pneumatic equipment on the sphere.

  16. Long-wearing TFE/metal bearings

    NASA Technical Reports Server (NTRS)

    Brass, R. A.; Gillon, W. A., Jr.

    1980-01-01

    Method for making metal/polytetrafluoroethylene (TFE) bearing surfaces embeds long-wearing layer of TFE in microscopic pits in metal. Technique has potential applications in automotive gears, ball joints, and roller chain components. Other applications are in use of unlubricated bearings in chemical, pharmaceutical, and food-processing equipment.

  17. Electrorheological fluid-controlled 'smart' journal bearings

    NASA Astrophysics Data System (ADS)

    Dimarogonas, Andrew D.; Kollias, Alexander

    1992-10-01

    The controllability of the stability properties of electrorheological (ER) fluid bearings is investigated using a specially developed solution of the lubricating equation for ER fluids. It was found that the properties of ER fluid bearings can be changed considerably by an applied electric field and that the stability region can be extended substantially.

  18. A flexible cruciform journal bearing mount

    NASA Technical Reports Server (NTRS)

    Frost, A. E.; Geiger, W. A.

    1973-01-01

    Flexible mount achieves low roll, pitch and yaw stiffnesses while maintaining high radial stiffness by holding bearing pad in fixed relationship to deep web cruciform member and holding this member in fixed relationship to bearing support. This mount has particular application in small, high performance gas turbines.

  19. Magnetic Bearings Would Increase Pump Efficiency

    NASA Technical Reports Server (NTRS)

    Studer, P. A.

    1983-01-01

    Active feedback applied to bearings windings compensate for unbalanced forces. Helical-screw rotation compresses and transports gas charges, which subject shafts to forces tend to displace them from their equilibrium positions. Magnetic bearings restore shafts to equilibrium, lowering friction and increasing efficiency.

  20. Long-wearing TFE/metal bearings

    NASA Technical Reports Server (NTRS)

    Brass, R. A.; Gillon, W. A., Jr.

    1980-01-01

    Method for making metal/polytetrafluoroethylene (TFE) bearing surfaces embeds long-wearing layer of TFE in microscopic pits in metal. Technique has potential applications in automotive gears, ball joints, and roller chain components. Other applications are in use of unlubricated bearings in chemical, pharmaceutical, and food-processing equipment.

  1. Self-adjusting magnetic bearing systems

    DOEpatents

    Post, Richard F.

    1998-01-01

    A self-adjusting magnetic bearing automatically adjusts the parameters of an axially unstable magnetic bearing such that its force balance is maintained near the point of metastable equilibrium. Complete stabilization can be obtained with the application of weak restoring forces either from a mechanical bearing (running at near-zero load, thus with reduced wear) or from the action of residual eddy currents in a snubber bearing. In one embodiment, a torque is generated by the approach of a slotted pole to a conducting plate. The torque actuates an assembly which varies the position of a magnetic shunt to change the force exerted by the bearing. Another embodiment achieves axial stabilization by sensing vertical displacements in a suspended bearing element, and using this information in an electrical servo system. In a third embodiment, as a rotating eddy current exciter approaches a stationary bearing, it heats a thermostat which actuates an assembly to weaken the attractive force between the two bearing elements. An improved version of an electromechanical battery utilizing the designs of the various embodiments is described.

  2. Methods and systems for micro bearings

    DOEpatents

    Stalford, Harold L

    2015-01-27

    A micro drive assembly may comprise a substrate, a micro shaft oriented in-plane with the substrate and at least one micro bearing to support rotation of the micro shaft. The micro shaft and micro bearing may be in or less than the micrometer domain.

  3. Lung alveolar epithelium and interstitial lung disease.

    PubMed

    Corvol, Harriet; Flamein, Florence; Epaud, Ralph; Clement, Annick; Guillot, Loic

    2009-01-01

    Interstitial lung diseases (ILDs) comprise a group of lung disorders characterized by various levels of inflammation and fibrosis. The current understanding of the mechanisms underlying the development and progression of ILD strongly suggests a central role of the alveolar epithelium. Following injury, alveolar epithelial cells (AECs) may actively participate in the restoration of a normal alveolar architecture through a coordinated process of re-epithelialization, or in the development of fibrosis through a process known as epithelial-mesenchymal transition (EMT). Complex networks orchestrate EMT leading to changes in cell architecture and behaviour, loss of epithelial characteristics and gain of mesenchymal properties. In the lung, AECs themselves may serve as a source of fibroblasts and myofibroblasts by acquiring a mesenchymal phenotype. This review covers recent knowledge on the role of alveolar epithelium in the pathogenesis of ILD. The mechanisms underlying disease progression are discussed, with a main focus on the apoptotic pathway, the endoplasmic reticulum stress response and the developmental pathway.

  4. Multigene deletions in lung adenocarcinomas from irradiated and control mice

    SciTech Connect

    Zhang, Y.; Woloschak, G.E.

    1996-06-01

    K-ras codon 12 point mutations mRb and p53 gene deletions were examined in tissues from 120 normal lungs and lung adenocarcinomas that were Formalin-treated and paraffin-embedded 25 years ago. The results showed that 12 of 60 (20%) lung adenocarcinomas had mRb deletions. All lung adenocarcinomas that were initially found bearing deleted mRb had p53 deletions (15 of 15; 100%). A significantly higher mutation frequency for K-ras codon 12 point mutations was also found in the lung adenocarcinomas from mice exposed to 24 once-weekly neutron irradiation (10 of 10; 100%) compared with those exposed to 24 or 60 once-weekly {gamma}-ray doses (5 of 10; 50%). The data suggested that p53 and K-ras gene alterations were two contributory factors responsible for the increased incidence of lung adenocarcinoma in B6CF{sub 1} male mice exposed to protracted neutron radiation.

  5. Lung diffusion testing

    MedlinePlus

    ... the blood from the lungs, and to allow carbon dioxide to "diffuse" from the blood into the lungs. How the Test is Performed You breathe in (inhale) air containing a very small amount of carbon monoxide and a tracer gas, such as methane ...

  6. Lung Cancer Indicators Recurrence

    Cancer.gov

    This study describes prognostic factors for lung cancer spread and recurrence, as well as subsequent risk of death from the disease. The investigators observed that regardless of cancer stage, grade, or type of lung cancer, patients in the study were more

  7. Artificial lung: current perspectives.

    PubMed

    Go, T; Macchiarini, P

    2008-10-01

    While the number of the patients suffering from end-stage pulmonary disease has been increasing, the most common treatment for this entity remains mechanical ventilation that entails the risks of lung damage by itself. Although the lung protective strategy for the prevention of further damage to the lung tissue has been elucidated and performed, mechanical ventilation alone as the management tactic coping with the patients of acute respiratory distress syndrome, chronic respiratory failure and lung transplantations has been a frustrated scenario. Extracorporeal membrane oxygenation or extracorporeal lung assist have been applied to these patients with occasional success, but it always accompanies difficulties such as multiple blood transfusion, labor intensity, technically complexity and tendency to infection. In contrast to advances in the development of cardiac or renal support systems for adults, the development of extra-, para- and intracorporeal mechanical systems for acute or chronic lung respiratory failure has logged far behind. It has been mostly due to the lack of the capable technologies. Entering 21st century with advent of new technology especially invention of the low resistance oxygenator, the developments of artificial lungs have entered the new stage. In this report current status of the artificial lungs will be reviewed.

  8. Lung Diseases and Conditions

    MedlinePlus

    ... Explore How the Lungs Work What Are... The Respiratory System What Happens When You Breathe What Controls Your Breathing Lung Diseases & Conditions Clinical Trials Links Related Topics Asthma Bronchitis COPD How the Heart Works Respiratory Failure Send a link to NHLBI to someone ...

  9. Lycopene and Lung Cancer

    USDA-ARS?s Scientific Manuscript database

    Although epidemiological studies have shown dietary intake of lycopene is associated with decreased risk of lung cancer, the effect of lycopene on lung carcinogenesis has not been well studied. A better understanding of lycopene metabolism and the mechanistic basis of lycopene chemoprevention must ...

  10. Indium lung disease.

    PubMed

    Cummings, Kristin J; Nakano, Makiko; Omae, Kazuyuki; Takeuchi, Koichiro; Chonan, Tatsuya; Xiao, Yong-Long; Harley, Russell A; Roggli, Victor L; Hebisawa, Akira; Tallaksen, Robert J; Trapnell, Bruce C; Day, Gregory A; Saito, Rena; Stanton, Marcia L; Suarthana, Eva; Kreiss, Kathleen

    2012-06-01

    Reports of pulmonary fibrosis, emphysema, and, more recently, pulmonary alveolar proteinosis (PAP) in indium workers suggested that workplace exposure to indium compounds caused several different lung diseases. To better understand the pathogenesis and natural history of indium lung disease, a detailed, systematic, multidisciplinary analysis of clinical, histopathologic, radiologic, and epidemiologic data for all reported cases and workplaces was undertaken. Ten men (median age, 35 years) who produced, used, or reclaimed indium compounds were diagnosed with interstitial lung disease 4-13 years after first exposure (n = 7) or PAP 1-2 years after first exposure (n = 3). Common pulmonary histopathologic features in these patients included intraalveolar exudate typical of alveolar proteinosis (n = 9), cholesterol clefts and granulomas (n = 10), and fibrosis (n = 9). Two patients with interstitial lung disease had pneumothoraces. Lung disease progressed following cessation of exposure in most patients and was fatal in two. Radiographic data revealed that two patients with PAP subsequently developed fibrosis and one also developed emphysematous changes. Epidemiologic investigations demonstrated the potential for exposure to respirable particles and an excess of lung abnormalities among coworkers. Occupational exposure to indium compounds was associated with PAP, cholesterol ester crystals and granulomas, pulmonary fibrosis, emphysema, and pneumothoraces. The available evidence suggests exposure to indium compounds causes a novel lung disease that may begin with PAP and progress to include fibrosis and emphysema, and, in some cases, premature death. Prospective studies are needed to better define the natural history and prognosis of this emerging lung disease and identify effective prevention strategies.

  11. Performance of a hybrid cylindrical roller bearing

    NASA Astrophysics Data System (ADS)

    Schrader, Stephen M.

    1992-08-01

    A 206-size hybrid (ceramic/steel) cylindrical roller bearing was tested in MIL-L-23699 C oil at several speeds and loads. Heat-generation data was collected and subsequently correlated with bearing-analysis software. Bearing-cage slip data was also collected at various oil-flow rates, oil temperatures, and with both MIL-L-7808 J and MIL-L-23699 C oils. The hybrid bearing was tested in MIL-L-23699 C oil for for 25 hours at 2220 N radial load and 1.08 MDN shaft speed. The hybrid bearing technology demonstrated in the report is applicable to the Integrated High Performance Turbine Engine Technology Initiative.

  12. Hybrid ceramic bearings for difficult applications

    SciTech Connect

    Dezzani, M.M.; Pearson, P.K.

    1996-04-01

    The Torrington Company, under contract from the Advanced Research Projects Agency (ARPA), has developed a hybrid bearing with improved properties for difficult applications. M50 and M50 NiL steel rings were nitrided to produce rolling contact raceway surfaces with hardnesses near Rockwell C 70. Rings were assembled with NBD-200 silicon nitride balls. Full-scale bearing tests were run under conditions that included 150 C temperature, surface flaws created by hard particle contamination, partial EHD lubrication, and the sliding action of balls running under thrust loading. The hybrid bearings had longer life than all steel bearings and demonstrated resistance to the surface peeling mode of failure initiation. Higher strength of the rolling contact surfaces, high residual compressive stresses in the nitrided layers, and a more favorable action in ceramic to steel rolling contact are discussed as the reasons for improved performance of the hybrid over all-steel bearings.

  13. 5-DOF Controlled Self-Bearing Motor

    NASA Astrophysics Data System (ADS)

    Ishikawa, Tatsuya; Matsuda, Ken-Ichi; Kondo, Ryou; Masuzawa, Toru

    A novel 5-DOF actively controlled self-bearing motor that combines the functions of a motor, two radial AMBs, and an axial AMB has been developed to achieve smaller size and higher performance simultaneously. In this paper, magnetic suspension performance of the 5-DOF controlled self-bearing motor is reported. First, radial control performance of the developed self-bearing motor is evaluated by the radial experimental setup. Next, tilt control performance and 5-DOF active control performance are evaluated by the 5-DOF experimental setup. Finally, the frequency response in the 5-DOF is measured with the contact-free levitation. The 5-DOF controlled self-bearing motor produced sufficient radial force and tilt control torque to overcome the radial negative stiffness and to stabilize the rotor. The sufficient frequency bandwidth was observed in the frequency response and the self-bearing motor successfully suppressed vibration at the resonant frequencies.

  14. Status of understanding for bearing materials

    SciTech Connect

    Bamberger, E.N.

    1984-04-01

    The structural materials and potential failure modes for high technology aircraft gas turbine bearings are reviewed. Among the failure modes discussed for iron-base through-hardened bearing materials are fatigue, surface distress, and corrosion. It is shown that the sub-surface initiated rolling-contact fatigue failure mode is reasonably well understood and in most cases can be controlled by proper material selection and design. Current bearing materials provide long life and high reliability in existing applications. A new generation of materials are being developed which will provide improved fracture toughness, better corrosion resistance, and a further extension of bearing fatigue life. Bearing problems due to surface distress, caused by a variety of surface and near surface anomalies, are less well understood. This area will require the implementation of an interdisciplinary effort to improve the level of understanding of metallic surface-lubricant reactions and interactions.

  15. Compact bearing cap for overhead camshaft

    SciTech Connect

    Bakker, E.A.M.

    1992-06-09

    This patent describes an internal combustion engine of the type having a cylinder head assembly with at least one rotatable camshaft with end journal portions mounted in semi-cylindrical bearings of the cylinder head, an improved camshaft retention arrangement for the end portion. It comprises a bearing cap with a semi-cylindrical portion at an opposite side of the camshaft journal as the cylinder head bearing portion, first fastener means extending through the the portion into the cylinder head to secure the bearing cap to the cylinder head; the semi-cylindrical portion of the bearing cap extending from the side portion about the camshaft journal and terminating just short of a second side of the camshaft so that an area of the cylinder head immediately adjacent the second side of the camshaft is available for placement of a second fastener means for securing the cylinder head to the engine.

  16. Development of new materials for turbopump bearings

    NASA Technical Reports Server (NTRS)

    Maurer, R. E.; Pallini, R. A.

    1985-01-01

    The life requirement for the angular contact ball bearings in the Space Shuttle Main Engine (SSME) high pressure oxygen turbopump (HPOTP) is 7.5 hours. In actual operation, significantly shorter service life was experienced. The objective is to identify bearing materials and/or materials processing techniques offering signficant potential for extending HPOTP bearing performance life. Interactive thermomechanical analysis of the HPOTP bearing-shaft system was performed with the SHABERTH computer program. Bearing fatigue life, ball-race contact stress, heat generation rate, bulk ring temperatures and circumferential stress in the inner rings were quantified as functions of radial load, thrust load and ball-race contact friction. Criteria established from the output of this analysis are being used for material candidate selection.

  17. Conservation of the Yellowstone grizzly bear

    USGS Publications Warehouse

    Mattson, David J.; Reid, Matthew M.

    1991-01-01

    We review literature relevant to the conservation of Yellowstone's grizzly bear population and appraise the bear's long-term viability. We conclude that the population is isolated and vulnerable to epidemic perturbation and that the carrying capacity of the habitat is likely to shift downward under conditions of climate change. Viability analyses based on the assumption that future habitats will closely resemble those existing at present have limited applicability; more information is needed on the autecology of important bear foods and on the implications of landscape-scale changes for bear population dynamics. Optimism over prospects of long-term persistence for Yellowstone's grizzly bears does not seem to be warranted and management of this population should be conservative and not unduly swayed on short-term positive trends.

  18. Genomic sequencing of Pleistocene cave bears.

    PubMed

    Noonan, James P; Hofreiter, Michael; Smith, Doug; Priest, James R; Rohland, Nadin; Rabeder, Gernot; Krause, Johannes; Detter, J Chris; Pääbo, Svante; Rubin, Edward M

    2005-07-22

    Despite the greater information content of genomic DNA, ancient DNA studies have largely been limited to the amplification of mitochondrial sequences. Here we describe metagenomic libraries constructed with unamplified DNA extracted from skeletal remains of two 40,000-year-old extinct cave bears. Analysis of approximately 1 megabase of sequence from each library showed that despite significant microbial contamination, 5.8 and 1.1% of clones contained cave bear inserts, yielding 26,861 base pairs of cave bear genome sequence. Comparison of cave bear and modern bear sequences revealed the evolutionary relationship of these lineages. The metagenomic approach used here establishes the feasibility of ancient DNA genome sequencing programs.

  19. Mobile bearings in primary knee arthroplasty.

    PubMed

    Vertullo, C J; Easley, M E; Scott, W N; Insall, J N

    2001-01-01

    Mobile-bearing knee arthroplasty (MBKA) has potential advantages compared with conventional fixed-bearing total knee arthroplasty (TKA). By allowing unconstrained axial rotation, MBKA can offer greater articular conformity without an increased probability of loosening due to increased axial torque. Increased articular conformity minimizes polyethylene contact stresses, thereby reducing linear wear and subsurface fatigue failure. Axial rotation of the platform also enables self-correction of tibial component malrotation. Despite these advantages, the long-term clinical results obtained with current MBKA devices are similar to those obtained with well-designed fixed-bearing TKA prostheses, with no data suggesting their superiority. The disadvantages of MBKA include bearing dislocation and breakage, soft-tissue impingement, a steep technique learning curve, and concerns about volumetric wear. Hypothetically, longer-term follow-up of MBKA results may reveal a significant difference from fixed-bearing TKA results as the fatigue failure threshold of incongruent polyethylene is exceeded.

  20. Ceramic Bearings For Gas-Turbine Engines

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1989-01-01

    Report reviews data from three decades of research on bearings containing rolling elements and possibly other components made of ceramics. Ceramic bearings attractive for use in gas-turbine engines because ceramics generally retain strengths and resistances to corrosion over range of temperatures greater than typical steels used in rolling-element bearings. Text begins with brief description of historical developments in field. Followed by discussion of effects of contact stress on fatigue life of rolling element. Supplemented by figures and tables giving data on fatigue lives of rolling elements made of various materials. Analyzes data on effects of temperature and speed on fatigue lives for several materials and operating conditions. Followed by discussion of related topic of generation of heat in bearings, with consideration of effects of bearing materials, lubrication, speeds, and loads.